ISTANBUL, Turkey — Leaders of NATO nations on Sunday night convened their first summit since the Iraq war and prepared to approve an agreement to train and equip Iraq's fledgling security forces.
White House officials described the anticipated deal as a significant step after more than a year of deep division within the alliance over the war.
But it also represented a serious lowering of expectations by the Bush administration, which had originally hoped that NATO countries would be willing to put troops on the ground, as they have in Afghanistan.
"This is pretty big stuff, especially in light of the debates" of the last year, a senior administration official said Sunday evening.
The official said the details, including how many forces NATO would train and how much training would occur outside Iraq, were still under discussion.
In recent weeks, the administration has lowered expectations for the summit, recognizing that NATO allies were unable to commit troops to Iraq because of their existing commitment in Afghanistan and opposition in their own countries.
The leaders of NATO's 26 members enjoyed a formal dinner Sunday night and were scheduled to hold meetings today and Tuesday -- the day before the United States returns sovereignty to Iraq.
Bush's visit to Turkey was shadowed by concern about the fate of three Turkish contractors held hostage in Iraq. They have been threatened with death unless other Turkish workers leave Iraq by Tuesday.
U.S. officials said the president discussed the hostage situation with the Turkish president and prime minister, but Bush did not respond to reporters' questions about it.
Turkish officials promised not to give in to terrorists' demands. "Turkey has been fighting terrorist activity for more than 20 years," said Turkish Defense Minister Vecdi Gonul. "They ask many things, they demand many things. We never consider them with seriousness."
Bush's visit was met with protests. About 25,000 people gathered in Istanbul, many holding signs that read, "Bush Go Home."
Tayfun Mater, a left-wing activist who helped organize the rally, said the hostage taking had given new motivation to the protesters. "The aim now in part is to help save the lives of those hostages," Mater said.
Some Turks said the hostage drama was likely to reduce public support for the Iraqi insurgency.
"A great majority of the Turkish people are opposed to U.S. occupation of Iraq and feel sympathy for the Iraqi resistance," said Oral Calislar, a columnist for the left-wing daily paper Cumhuriyet, in an interview.
"But such atrocities and the targeting of Turks by Al Qaeda has triggered loathing among the Turkish people and a weakening of support for the resistance fighters in Iraq," he said.
"I don't like what America is doing to the Iraqis, but innocent Muslim Turks should not be paying the price for American crimes," said Ferit Hamamcioglu, a waiter in Ankara, the Turkish capital.
The protests and the presence of heads of state and government led to severe security restrictions in Istanbul, an ancient port city where last week's bombings and the Iraq abductions increased tensions over the weekend.
Anti-riot fencing sealed off much of the city center, and residents were forced to carry passes to reach their homes. Turkish naval vessels patrolled offshore and helicopters buzzed overhead.
Bush spent the first half of the day with Turkish leaders in Ankara, where he placed a wreath at the mausoleum of Kemal Ataturk, the founder of the modern, secular Turkish state.
Throughout his visit, the president has praised Turkey as a secular yet Muslim nation, the kind of democracy he hopes other nations, including Iraq, will emulate.
"I appreciate so very much the example your country has set on how to be a Muslim country and at the same time, a country which embraces democracy and rule of law and freedom," Bush said as he met with Turkish Prime Minister Recep Tayyip Erdogan in Ankara.
Bush's first meeting in Istanbul was with a group of religious leaders, including an Islamic cleric, Turkey's chief rabbi and Bartholomew I, the spiritual leader of the world's Eastern Orthodox Christians. Istanbul, previously known as Constantinople, was the birthplace of Orthodox Christianity, but the country is now 99% Muslim.
The religious leaders "represent the very best of Turkey, which is a country that is secular in politics and strong in its faith," Bush said after the meeting.
Administration officials described the summit as a new stage in the alliance's history. Until recently, the North Atlantic Treaty Organization believed that its mission of defending Europe and North America had limited its activity to those continents.
But nearly three years after the Sept. 11 attacks, U.S. officials say the alliance now agrees that defending itself means addressing threats that arise outside its traditional geographic sphere.
"The debate about what NATO is for is answered, and the question now is how NATO is going to do that," the administration official said.
Turkey is the only Muslim member of the alliance, and its role as a mediator between the Western and Islamic worlds has come to the fore amid Bush's campaign for democracy in the Middle East.
Last year, relations between Turkey and the United States were strained when the Turkish parliament turned down U.S. requests to use the nation as a base for military operations in northern Iraq.
Both sides say those tensions have passed. Bush complimented Turkish efforts to bring peace to the divided island of Cyprus.
But U.S. officials did not accede to Turkish requests to crack down on the militant PKK, or Kurdistan Workers Party, which attacks Turkey from bases in northern Iraq. They offered assurances, however, that the United States viewed the PKK as a terrorist group.
Special correspondent Amberin Zaman contributed to this report from Ankara and Istanbul.