Correspondents say it will avoid specific proposals but will cover all major regional issues, including Iran and the Israeli-Palestinian question.

As Mr Obama arrived in Egypt, Iran's supreme leader Ayatollah Ali Khamenei said the US was still "deeply hated" in the Middle East.

Earlier, Mr Obama held talks in Riyadh with King Abdullah of Saudi Arabia.

'Truth-telling'

After landing in Cairo, Mr Obama headed in his motorcade to the Kuba palace along streets empty except for the soldiers lining the route.

Mr Obama then held talks with Egyptian President Hosni Mubarak.

OBAMA'S TOUR 3 June: Saudi Arabia - talks with King Abdullah on Israel-Palestinian peace negotiations 4 June: Egypt - talks with President Hosni Mubarak, keynote speech at Cairo university 5 June: Germany - meets Chancellor Angela Merkel, visits to Dresden and to Buchenwald concentration camp 6 June: France - meets President Nicolas Sarkozy, attends D-Day events in Normandy

Mr Mubarak said the pair had a "candid and frank" discussion of "all problems in the region", including Iran.

Mr Obama said: "We discussed the situation between Israel and the Palestinians. We discussed how we can move forward in a constructive way that brings about peace and prosperity for all people in the region."

He said the US was committed to working in partnership with countries in the Middle East.

Mr Obama visited the Sultan Hassan mosque ahead of his speech at Cairo University.

Mr Obama's aides said the speech, to be broadcast to an audience of millions around the world, would be a "truth-telling" exercise.

The BBC's Christian Fraser in Cairo says Barack Obama wants to give a message of respect to a region which has often felt ignored, misunderstood or patronised by the US.

Our correspondent says conservative elements in Egypt have suggested they are prepared to listen to Mr Obama as long as there is substance behind the rhetoric.

The president is expected to use the speech to discuss the current state of peace talks between Israel and the Palestinians and to set out how he views the conflict.

He will not include any specific proposals, but will articulate what he believes both sides need to do to resolve the current stalemate, says our correspondent.

White House officials have said that one speech alone will not heal divisions but could start a process to "re-energise the dialogue with the Muslim world".

Presidential advisers said there would be a "forthright discussion" of democracy, human rights and nuclear non-proliferation.

However, they denied Mr Obama had issued any ultimatum to Israel on the question of settlement building in the West Bank.

Israel is resisting calls to freeze building activity in all settlements, but Palestinian leaders have said there can be no progress towards peace without a halt to such construction.

'Action is needed'

As Mr Obama arrived in Egypt, Ayatollah Ali Khamenei delivered a speech to mark the 20th anniversary of the death of Ayatollah Ruhollah Khomeini, the founder of Iran's Islamic Republic.

Mr Obama was presented with Saudi Arabia's highest honour

Ayatollah Khamenei said: "The nations of this part of the world... deeply hate America. Even if they give sweet and beautiful [speeches] to the Muslim nation that will not create change. Action is needed."

On the Saudi Arabia leg of his tour, Mr Obama held talks with King Abdullah.

The president was presented with the King Abdul Aziz Order of Merit, the kingdom's highest honour.

King Abdullah said the medallion was "only given to the very few friends of the king" and that Mr Obama was "certainly one of those".

As Mr Obama arrived in Saudi Arabia, Arabic television station Al Jazeera broadcast a message said to be from al-Qaeda leader Osama Bin Laden.

The message accused Mr Obama of ordering Pakistan to crack down on militants in the Swat valley and said Mr Obama and his administration had "sown new seeds to increase hatred and revenge on America".

White House spokesman Robert Gibb said it was not surprising that al-Qaeda "would want to shift attention away from the president's historic and continued efforts to have an open dialogue with the Muslim world".

Apart from a stop-over in Iraq in April, this is Mr Obama's first time in the region since becoming president.

Mr Obama hopes to set a new tone which is designed to isolate extremists in the region and re-establish the understanding the US gained after 9/11 and lost over Iraq, says the BBC's Paul Reynolds.

After Cairo, Mr Obama will travel on to Europe for D-Day commemorations.

The BBC News website will carry a fully-annotated transcript of President Obama's Cairo speech, with analysis of key passages by BBC world affairs correspondent Paul Reynolds.

LOS ANGELES – Actor James Franco says he has dropped a plan to give a commencement speech at the University of California, Los Angeles, a move that may have been prompted by pressure from students.

Franco issued a statement saying he canceled his June 12 appearance because of conflicts with preproduction demands for his next film.

However, the "Pineapple Express" star had been the object of opposition from students who said he was not the right fit for the commencement speech.

"The problem with him as a speaker comes down to the fact he was a peer for so many of us," UCLA senior Erin Moore said. "He was in our class. He's not a role model. And he hasn't had time to accomplish anything with his degree."

Franco, 31, enrolled at UCLA in 1996 and graduated last year with a degree in creative writing. He would have been the youngest person and most recent graduate to deliver a commencement speech at UCLA.

Soon after the commencement announcement in March, Moore set up a Facebook page called "UCLA Students Against James Franco as Commencement Speaker." Hundreds joined, and Moore estimated about 80 percent of them are UCLA students.

A call to Franco's manager early Saturday was not immediately returned. A UCLA spokesman referred The Associated Press to Franco's statement, in which he expressed regret at not being able to give the speech.

UCLA announced on its Web site that Franco would be replaced by Linkin Park lead guitarist and UCLA alumnus Brad Delson, who graduated with a bachelor's degree in communication studies in 1999.

Franco is perhaps best known for his supporting role in the "Spider-Man" films.

He is preparing for the comedy "Your Highness," which is set to begin filming next month. Amanda Lundberg, a spokeswoman for the producer of the film, said Franco would be on the set in Ireland on June 12.

Distraught relatives have been going through days of anguish

Two bodies and debris have been found from the Air France plane which went missing over the Atlantic last Monday, the Brazilian air force has said.

The remains were picked up some 800km (500 miles) north-east of Fernando de Noronha islands, off Brazil's coast.

Experts on human remains are on their way to examine the find.

All 228 passengers and crew on board AF 447 are believed to have been killed when the plane disappeared during its flight from Rio de Janeiro to Paris.

"We confirm the recovery from the water of debris and bodies from the Air France plane," air force spokesman Jorge Amaral told reporters in the northern city of Recife on Saturday.

He later added that two male bodies had been found, as well as objects linked to passengers known to be on the flight, including a suitcase with a plane ticket and a backpack with a computer inside.

"It was confirmed with Air France that the ticket number corresponds to a passenger on the flight," Col Amaral said.

A blue seat was also found, and Air France is checking the serial number to see whether it came from the flight.

The remains were found not far from where the last signal from the plane was received and taken to the islands of Fernando de Noronha.

Flight recorders

The items were the first to be definitely linked to the plane, nearly six days after the crash.

SEARCH FOR FLIGHT AF 447 1 June: Contact lost with plane over mid-Atlantic 2 June: First debris spotted from the air includes an airline seat. Brazilian defence minister says debris is from missing plane 3 June: More debris spotted, including a 7m-wide chunk of metal. Fuel slick seen on ocean surface 4 June: Buoys and pallet recovered from ocean said to be from plane. Officials later retract statement 6 June: First two bodies, plus suitcase and backpack found, along with seat thought to be from the plane Timeline of Flight AF 447 Air disasters timeline Mystery of Air France flight Challenge of deep-sea debris

But the BBC's Gary Duffy in Sao Paulo says the authorities are adopting a cautious approach after previous reports of debris being found proved false.

Correspondents say that much of the search effort so far has been focused on finding flight data recorders, which have sonar beacons - or "pingers" - attached to them.

But French officials say there was no guarantee the beacons were still attached to the flight recorders, and they may have been separated in the impact of the crash.

The officials do not know what triggered the plane's problems, but it was flying through an area of thunder storms and turbulence.

They said it sent 24 error messages minutes before it crashed.

A French submarine is being sent to join in the search since it had sonar equipment that could help locate the airliner's flight data recorders.

The US is also sending specialised listening equipment.

RECIFE, Brazil – Searchers found two bodies and a briefcase containing a ticket for Air France Flight 447 in the Atlantic Ocean close to where the jetliner is believed to have crashed, a Brazil military official said Saturday.

The French agency investigating the disaster, meanwhile, said airspeed instruments on the plane were not replaced as the maker recommended before it disappeared in turbulent weather nearly a week ago.

The French accident investigation agency, BEA, found the plane received inconsistent airspeed readings from different instruments as it struggled in a massive thunderstorm on its flight from Rio de Janeiro to Paris with 228 people aboard.

Airbus had recommended that all its airline customers replace speed-measuring instruments known as Pitot tubes on the A330, the model used for Flight 447, said Paul-Louis Arslanian, the head of the agency.

"They hadn't yet been replaced" on the plane that crashed, said Alain Bouillard, head of the French investigation. Air France declined immediate comment.

Arslanian of the BEA cautioned that it is too early to draw conclusions about the role of Pitot tubes in the crash, saying that "it does not mean that without replacing the Pitots that the A330 was dangerous."

He told a news conference at the agency's headquarters near Paris that the crash of Flight 447 does not mean similar planes are unsafe, adding that he told family members not to worry about flying.

Airbus had made the recommendation for "a number of reasons," he said.

The two male bodies were recovered Saturday morning about 70 kilometers (45 miles) south of where Air France Flight 447 emitted its last signals — roughly 400 miles (640 kilometers) northeast of the Fernando de Noronha islands off Brazil's northern coast.

Brazilian air force spokesman Col. Jorge Amaral said an Air France ticket was found inside a leather briefcase.

"It was confirmed with Air France that the ticket number corresponds to a passenger on the flight," he said.

Admiral Edison Lawrence said the bodies were being transported to the Fernando de Noronha islands for identification. A backpack with a vaccination card also was recovered.

The finds could potentially establish a more precise search area for the crucial black box flight recorders that could tell investigators why the jet crashed, although Brazilian authorities refused to comment on implications for the search.

Investigators have been searching a zone of several hundred square miles (square kilometers) for debris. A blue plane seat with a serial number on it has been recovered — but officials were still trying to confirm with Air France that it was a seat belonging to Flight 477.

The investigation is increasingly focused on whether external instruments may have iced over, confusing speed sensors and leading computers to set the plane's speed too fast or slow — a potentially deadly mistake in severe turbulence.

Pitot tubes, protruding from the wing or fuselage of a plane, feed airspeed sensors and are heated to prevent icing. A blocked or malfunctioning Pitot tube could cause an airspeed sensor to malfunction and cause the computer controlling the plane to accelerate or decelerate in a potentially dangerous way.

Air France has already replaced the Pitots on another Airbus model, the 320, after its pilots reported similar problems with the instrument, according to an Air France air safety report filed by pilots in January and obtained by The Associated Press.

The report followed an incident in which an Air France flight from Tokyo to Paris reported problems with its airspeed indicators similar to those believed to have been encountered by Flight 447. In that case, the Pitot tubes were found to have been blocked by ice.

"Following similar problems frequently encountered on the A320 fleet, preventative actions have already been decided and applied," the safety report says. The Pitots on all Air France's A320s were retrofitted with new Pitots "less susceptible to these weather conditions."

The same report says Air France decided to increase the inspection frequency for its A330 and A340 jets' Pitot tubes, but that it had been waiting for a recommendation from Airbus before installing new Pitots.

As they try to locate the wreckage, investigators are relying on 24 messages the plane sent automatically during the last minutes of the flight.

The signals show the plane's autopilot was not on, officials said, but it was not clear if the autopilot had been switched off by the pilots or had stopped working because it received conflicting airspeed readings.

The flight disappeared nearly four hours after takeoff, killing all on board. It was Air France's deadliest plane crash and the world's worst commercial air accident since 2001.

The head of France's weather forecasting agency, Alain Ratier, said weather conditions at the time of the flight were not exceptional for the time of the year and region, which is known for violent stormy weather.

On Thursday, European plane maker Airbus sent an advisory to all operators of the A330 reminding them of how to handle the plane in conditions similar to those experienced by Flight 447.

Peter Goelz, a former managing director of the National Transportation Safety Board, said that advisory and the Air France memo about replacing flight-speed instruments "certainly raises questions about whether the Pitot tubes, which are critical to the pilot's understanding of what's going on, were operating effectively."

Arslanian said it is vital to locate a small beacon called a "pinger" that should be attached to the cockpit voice and data recorders, now presumed to be deep in the Atlantic.

"We have no guarantee that the pinger is attached to the recorders," he said.

Holding up a pinger in the palm of his hand, he said: "This is what we are looking for in the middle of the Atlantic Ocean."

Currents could have scattered debris far along the ocean floor, he said.

President Barack Obama said at a news conference with French President Nicolas Sarkozy Saturday that the United States had authorized all of the U.S. government's resources to help investigate the crash.

BEA head Arslanian said U.S. forces have lent the agency acoustic systems that will be fitted to two naval vessels. France's Emeraude submarine and other high-tech equipment from French marine research institute Ifremer are also being sent to the region.

The submarine, to arrive next week, will try to detect signals from the black boxes, said military spokesman Christophe Prazuck.