At a summit designed to emphasize NATO's unity after deep divisions caused by the U.S.-led war on Iraq 15 months ago, France and the United States also clashed over Afghanistan and Turkey's relations with the European Union.
The friction came as Afghan President Hamid Karzai implored NATO leaders Tuesday to overcome months of foot-dragging and send more troops to his country ahead of September elections.
"Please hurry," Karzai said. "Come sooner than September and provide the Afghan men and women with a chance to vote freely without fear, without coercion."
As the alliance struggles to define its role in a post-Cold War world, French President Jacques Chirac forcefully stated his opposition to any collective NATO presence on the ground in Iraq, suggesting it should limit its role to coordinating national efforts and training outside the country.
"I am completely hostile to the idea of a NATO establishment in Iraq," Chirac told a news conference. "It would be dangerous, counterproductive and misunderstood by the Iraqis, who after all deserve a little bit of respect."
American officials insisted the training program should be a centralized operation under a NATO command in Iraq, although they accepted that reluctant countries such as France and Germany could limit their contribution to training outside the country.
With all allies stressing the urgency of sending help to the fledgling Iraqi forces following the transfer of power to the new government Monday, the debate on how NATO puts its agreement into practice is expected to start when envoys from the alliance meet Thursday in Brussels.
Chirac says he is reluctant to send NATO troops to Iraq because it would be seen as legitimizing a war and occupation that France believes was contrary to international law. Chirac, and his German counterpart Gerhard Schroeder, could also be angling to get repayment of debts that Iraq owes their countries.
On Afghanistan, Chirac rejected an American proposal that NATO's elite new response force be deployed to provide security for elections scheduled in September.
France agreed with other allies that NATO should send hundreds more troops for the elections in reply to Karzai's request, but said the response force should be used only for emergency situations, not for peacekeeping.
The force is "meant to act in a known crisis, which is obviously not the case in Afghanistan today," Chirac said Monday, the first day of the summit. Diplomats said the issue provoked a sharp exchange in Istanbul between Defense Secretary Donald Rumsfeld and his French counterpart, Michele Alliot-Marie.
France was not the only country with reservations, but the Americans said the force would be an ideal solution to NATO's difficulties in mustering European troops for Afghanistan. As usual, the United States was backed by Britain.
"The key is that the response force NATO has is deployed to help the elections," said Prime Minister Tony Blair.
One possible solution could be using the NATO Response Force as an "over the horizon" force held in reserve to help peacekeeping in Afghanistan in a crisis. Officials said a reconnaissance team from the force could visit Afghanistan soon to assess how it could be involved.
Karzai has long appealed for NATO to expand its "security assistance" force, which has been restricted to the Afghan capital, Kabul.
The alliance agreed in October to expand the force but has been unable to persuade governments to provide needed troops, apart from Germany, which sent 240 soldiers to the northern Afghan city of Kunduz.
The months of delays have cast doubt on NATO's credibility as it seeks to reinvent itself as a global security force in the post-Cold War era.
On Turkey, Chirac accused President Bush of meddling in the European Union's affairs by pushing for the EU to bring Turkey into its ranks.
"It's a bit like if I told the United States how they should manage their relations with Mexico," the French leader said.
The Franco-American wrangling is nothing new in NATO. Charles DeGaulle pulled France out of the military part of the alliance during an earlier spat.