Updated

President Bush is participating in all the fanfare that precedes Monday's summit of 26 NATO (search) countries starting with a lavish dinner for heads of state.

Bush arrived Sunday evening in Istanbul, where he headed to the famed Dolmabahce Palace (search) after meeting with a group of religious leaders he thanked for not demanding more political power. Bush said Turkey is a model for the region in that it is almost entirely Muslim, but is also secular and democratic.

"It has been my honor to welcome these very important leaders of different faiths to this dialogue. They represent the very best of Turkey which is a country that is secular in politics, and strong in its faith," Bush said.

After meeting with those leaders, Bush then sat down with NATO Secretary-General Jaap de Hoop Scheffer (search). NATO's defense ministers are in attendance for the summit, and are expected to set new targets for their armed forces, which are currently better placed to fight the former Soviet Union than to address the challenges confronting the world today.

"I was hoping to change the mission of NATO so it meets the threats of the 21st century, and we're going to work together to help make sure NATO is configured militarily to meet the threats of the 21st century as well," Bush told reporters.

"We have terrorism everywhere. There's fights everywhere, be it here in this city, be it in New York, Uzbekistan, Mombasa, Yemen, you name it. This alliance has to participate in fighting it first, and winning it," De Hoop Scheffer said.

The most current and urgent threat now faces Iraq, whose interim government is scheduled to take over sovereignty this week. The administration has been seeking help from NATO to train Iraqi troops so that the United States can begin to reduce its forces there.

NATO leaders are expected to vote on a request from the new Iraqi government for help in training its security forces. That ran into resistance from German officials, who said they won't send troops to Iraq to train, but will train a limited number of Iraqis in Germany. National Security Adviser Condoleezza Rice said that's better than nothing.

"There is a very good chance we will get a positive answer to Prime Minister Allawi's request for training, and also a strong political commitment," National Security Adviser Condoleezza Rice told Fox News Sunday.

"NATO will urge that this all happen on a very urgent basis, that this isn't a long planning exercise, that really they're in a phase of looking to quick implementation of these plans," Rice said.

Defense Secretary Donald Rumsfeld told British television an agreement in principle has been reached, and he expects it to be approved.

"We anticipate at this summit, the heads of state will end up agreeing that NATO, the North Atlantic Treaty Organization, will in fact have a role in training and equipping the Iraqi security forces, which is a very good thing if that happens."

With the kidnapping of three Turkish workers, however, the meeting had an ominous undertone. Insurgents in Iraq say they will kill the hostages unless Turkish companies stop aiding U.S. forces in Iraq. Turkey previously refused to send troops into its southern neighbor and did not permit the United States to use bases there to launch its attack during the war last year.

In addition, insurgents took a Pakistani hostage Sunday and threatened to behead him in three days if their allies are not freed from prison. Pakistan is not a NATO partner.

Turkey is a country very much divided over the summit. The government wanted very much to host NATO's leaders, but the war in Iraq is not popular with the Turkish people.

In addition, some Islamic fundamentalists say Turkey's push to join the European Union shows it is turning its back on its neighbors in the Arab world. But Bush's call to Europe to set a deadline to grant Turkey's decades-long pursuit to become an EU member gained him favor among supporters of that goal.

Security in Turkey is extraordinarily tight. Two bomb explosions several days ago killed four people and explosives were found a couple of days ago in the airport where Bush landed early Sunday. Tens of thousands of police and soldiers are on patrol. The Bosphorus Strait (search), which connects Europe and Asia by joining the Black Sea with the Mediterranean, is closed to the oil tankers that usually pass through the straits daily.

Fox News' Wendell Goler and Jim Angle contributed to this report.