LONDON U.S. President Barack Obama on Wednesday declared the U.S.-European alliance as vital as ever and said it must use its influence to push for democratic reforms in the Middle East.
Obama outlined a manifesto for responding to the "Arab Spring" uprisings as he became the first U.S. president to address both houses of the British parliament in Westminster Hall, whose walls are steeped in 1,000 years of history.
"Ultimately, freedom must be won by the people themselves, not imposed from without. But we can and must stand with those who so struggle," he said.
His speech was aimed at reassuring Europe, where there is some sense that the United States is turning its attention elsewhere in the face of fierce diplomatic challenges from Asia and the Arab world.
In a speech anchoring his four-nation European trip, Obama said it was up to the United States, Britain and their European allies to lead at a time when the world was being tested by economic turmoil, Arab revolutions, Islamic militants, climate change and efforts to spread nuclear weapons.
It is a message he will carry Thursday to Deauville, France, where leaders of the Group of Eight powers meet.
The audience at Westminster Hall, which has been used for coronation banquets and the lying-in-state of deceased monarchs, included former prime ministers Tony Blair, Gordon Brown and John Major and even American actor Tom Hanks.
All applauded when Obama, who had played up his Irish roots in Ireland earlier in the week, said it was an honour "for the grandson of a Kenyan who served as a cook in the British Army to stand before you as president of the United States."
Obama rejected those who say the time of American and European influence around the world has passed as the likes of China, Brazil and India claim a bigger place on the world stage.
"That argument is wrong," he said. "The time for our leadership is now ... Our alliance will remain indispensible to the goal of a century that is more peaceful, more prosperous and more just."
Obama and his wife Michelle enjoyed a final round of pomp by hosting a dinner in honour of Queen Elizabeth and attended by such luminaries as "Harry Potter" author J.K. Rowling, actor Colin Firth of "The King's Speech" and soccer star David Beckham.
A public opinion survey by Britain's Channel 4 News found Britons split over the future of its "special relationship" with America. Forty-two percent of those surveyed said the relationship should continue, and 39 percent said it should end.
"BROADER PARTNERS NEEDED"
Robin Niblett, director of the foreign policy think tank Chatham House, told Reuters that the priorities Obama had listed at Westminster Hall "are going to require a broader set of partners than were in this chamber."
At home, critics have accused Obama of responding too slowly to developments in the Arab world and contributing to a stalemate in Libya, where leader Muammar Gaddafi is showing no sign of yielding to a rebellion.
With some wondering why he has not applied similar pressure to President Bashar al-Assad to stop a bloody crackdown in Syria, Obama said: "We cannot stop every injustice."
Obama, who is under pressure at home not to engage in another foreign military entanglement, cautioned that it would take time for the uprisings in a string of nations from Egypt to Syria to play themselves out.
"It will be years before these revolutions reach their conclusion, and there will be difficult days along the way. Power rarely gives up without a fight," he said.
Eager to begin removing some U.S. troops from Afghanistan in July, Obama said the United States was now preparing to turn a corner there and that, during the transition period, "we will pursue a lasting peace with those who break from al Qaeda and respect the Afghan constitution."
Earlier, at a joint news conference, Obama and British Prime Minister David Cameron predicted that Gaddafi would ultimately leave power. Cameron did not deny French reports that Britain is considering using attack helicopters alongside France against Libyan targets to increase the heat on Gaddafi.
"We will be looking at all the options for turning up that pressure," he said when asked about the helicopters.