But he made a parting plea to world leaders wrapping up a three-day summit of the powerful Group of Eight nations to do what they can to guide Iraq into a stable democracy.
"They need our help, and they will have our help," Mr. Bush said at a news conference here concluding the summit on nearby Sea Island, Georgia.
British Prime Minister Tony Blair also said it was not practical to have a large number of NATO troops in Iraq, but suggested the alliance could help out with training.
"Our desire is not to have a large number NATO troops there," Blair said. "I don't think that is practical. Our desire is ... to have NATO help with the training, in other words with the building up of the Iraqi capability."
Blair said he believed that the disagreement over NATO's role "will be overcome."
Both French President Jacques Chirac and German Chancellor Gerhard Schroeder were skeptical of Mr. Bush's suggestion for an expanded NATO role.
Chirac, who had a one-on-one meeting with Mr. Bush Thursday, has strong reservations, but is open to discussions before a NATO summit in Turkey at the end of the month, a French official said.
On Wednesday, Chirac said "I don't think it is NATO's purpose to intervene in Iraq."
Schroeder, who made clear his own country will not send troops, said Thursday that "the German position hasn't changed, but we have also made it clear that the decision of the NATO members who are involved in Iraq won't be blocked."
Mr. Bush admitted as much, telling reporters: "I don't expect more troops from NATO to be offered up. That is an unrealistic expectation."
Four of the G-8 countries, the United States, Britain, Italy and Japan, have forces in Iraq. The other four — France, Germany, Russia and Canada — do not.
A U.N. Security Council resolution on Iraq approved on Tuesday will have the "practical effect" of allowing the leaders of countries with troops already in Iraq to persuade their governments to keep them there, Mr. Bush said.
Despite the disagreement on NATO's possible role, Mr. Bush said the United States and France now have "excellent" relations.
While Iraq and the wider Middle East dominated the summit, the leaders did reach modest agreements on other issues, such as training 75,000 new peacekeepers, primarily to assist in Africa, over the next five years, and coordinating efforts to find a vaccine against the HIV virus that causes AIDS.
The G-8 issued an appeal to the United Nations to help prevent a humanitarian catastrophe in Sudan, where ethnic violence in the western Darfur region has displaced more than a million people.
A joint statement voiced concern about reports that Arab militias are carrying out an ethnic cleansing campaign against black Africans in Darfur.
The summit also approved a 28-point plan to further strengthen airport security while trying not to burden travel with unnecessary and costly screening.
The U.S. administration was eager promote the accords as proof that Mr. Bush is a leader able to get things done on the global stage. He has been accused of alienating many of America's traditional allies.
Among the agreements announced on the concluding day of the summit, the G-8: