By ALISTAIR MACDONALD And CAROL E. LEE
LONDON—U.S. President Barack Obama and British Prime Minister David Cameron warned that military operations in Libya will be a long slog that continues until Col. Moammar Gadhafi leaves power, a shift from the president's initial stance that the military intervention in Libya would be limited in nature.
Mr. Obama's remarks—first in a news conference with Mr. Cameron, then in a high-profile speech before both houses of Parliament—made clear that the U.S. and its allies are bracing for a long battle not just to remove Col. Gadhafi from power, but also to guide the burgeoning democracy movement in other Arab nations to a successful conclusion.
Within Westminster Hall, the 900-year-old hall that fermented the early development of Britain's democracy and law courts, Mr. Obama used his speech to set the Libyan effort—and U.S. assistance in the so-called Arab Spring—against a backdrop of the West's historical fight for democracy, free enterprise and innovation. In that process Mr. Obama said the U.S. has had no greater ally than the U.K.
He described such operations as a mark of how the alliance between the U.K. and the U.S. remains the "greatest catalyst for global action" even as people predict their power is being encroached upon by emerging giants such as China and India.
Photos: President Obama in London
He added: "As millions are still denied their basic human rights because of who they are, or what they believe, or the kind of government that they live under, we are the nations most willing to stand up for the values of tolerance and self-determination that lead to peace and dignity."
In both appearances, Mr. Obama stressed that a long game is under way throughout the Middle East. He said military action in Libya is going to be "a slow, steady process in which we're able to wear down the regime forces and change the political calculations of the Gadhafi regime to the point where they finally realize that they're not going to control this country."
He said there were no "artificial" timetables for U.S. forces to pull back. Both leaders once again ruled out sending in ground forces.
The U.S. position has evolved from being one of limited intervention to one where Mr. Obama is now preparing the country for a lengthy battle. In recent days, North Atlantic Treaty Organization forces have intensified their bombing of Col. Gadhafi's military, sinking naval ships and destroying regime headquarters in Tripoli.
Later, in his speech to Parliament, Mr. Obama said the move toward democracy throughout the Middle East will be a lengthy process that requires patience.
"It will be years before these revolutions reach their conclusion, and there will be difficult days along the way," Mr. Obama said. "Power rarely gives up without a fight."
Mr. Obama said that if countries like the U.K. and U.S. fail to take up their global responsibilities, "who would take our place?"
He said the emerging giants that are predicted to overtake Western influence have prospered in a world created by the U.S. and Europe.
He set out a future world in which the two countries and the wider Europe would act as standard bearers for the open markets and individual liberties through which everyone will benefit.
Mr. Obama acknowledged that in fighting terror, the U.S. and U.K. have partnered with countries that don't encourage "the freedoms" that he espouses, in a reference that could point to a host of countries, from Pakistan to Saudi Arabia, with which the U.S. and U.K. work.
The president's weeklong visit to Europe is in part aimed at resetting his relationship with the Continent, a region that has felt somewhat ignored by his presidency.
U.K. officials—always sensitive about the status of Britain's "special relationship" with the U.S.—have touted its rebranding as an "essential" relationship. Upon taking office, both leaders had been expected to subtly downgrade the relationship.
In the past, Mr. Obama has spoken of being "America's first Pacific president," while Mr. Cameron has said he would make Britain's relationship with the U.S. less "slavish" and would look to create a new "special relationship" with India.
But this week, neither leader showed any sign of swaying from an association that has seen 10,000 British troops join U.S. forces in Afghanistan and puts each other among their largest single trading partners.
The leaders successfully put on a unified front throughout Mr. Obama's two-day visit. But on a couple of key points, they attempted to artfully dodge their differences.
Mr. Cameron's opening remarks to the news conference appeared to indicate that his U.S. counterpart would agree that aggressive spending cuts and tax increases were the right way to tame the debt piles both face.
That would have been a key endorsement of the British leader's often-unpopular program, countering critics who contrast Mr. Cameron's tougher and faster cuts with those in the U.S.
In answering a question, however, Mr. Obama avoided such an endorsement and concluded: "We may take slightly different paths but we want to end up in the same place."
For Mr. Obama, the U.K. prime minister stopped short of saying, as the U.S. wants, that the U.K. won't support the Palestinian effort to achieve United Nations-sanctioned statehood through a General Assembly vote in September.
"We want to discuss this within the European Union and try and maximize the leverage and pressure that the European Union can bring frankly on both sides to get this process moving," Mr. Cameron said.
Mr. Obama had vowed to make the case against U.N.-sanctioned statehood in his private meetings with other leaders, such as Mr. Cameron. The president also meets this week with French President Nicolas Sarkozy and the heads of several Central and Eastern European nations.
"What the United Nations is not going to be able to do is deliver a Palestinian state," Mr. Obama said.
Write to Alistair MacDonald at email@example.com