NATO ambassadors have failed once again to resolve a standoff over a proposal that would see the alliance begin planning for Turkey's defense in the event of a war in Iraq. France, Belgium and Germany continue to insist that no such move should be undertaken until diplomatic efforts to solve the Iraq crisis are exhausted.

For the third day in a row, NATO was incapable of breaking a deadlock that has thrown the alliance into one of its worst crises ever.

Over the past three weeks, France, Germany and Belgium have blocked a U.S. request that the alliance provide indirect support for any U.S.-led war against Iraq.

The U.S. proposal called on NATO to take steps to protect Turkey against any Iraqi counterstrike if war breaks out by planning for the deployment of surveillance aircraft and anti-missile systems to the only NATO ally bordering Iraq.

It also called on the allies to protect U.S. bases in Europe and send troops to replace any U.S. units in the Balkans that may be transferred to the Gulf.

France, Germany and Belgium argue that such moves would put the alliance on a war footing. And they say that would undermine peace efforts.

With the impasse dragging on, NATO Secretary-General George Robertson put forth a compromise proposal Wednesday that was limited to planning for Turkey's defense.

Turkey asked the alliance on Monday for help, saying it would be threatened in case of war.

After meeting briefly in the morning and then consulting with their governments in the afternoon, the ambassadors returned to the NATO conference room Wednesday evening. But the three holdouts still would not agree to the compromise proposal.

All three say they are ready to help protect Turkey, but that the time is not yet right to plan for its defense.

NATO spokesman Yves Brodeur said the issue is not "whether" but "when." "The issue is not substance. It's a question of timing. The three delegations who have difficulties with the proposal are all saying that they haven't changed their mind, their stance on this. They still feel that the time is not right for NATO to make a decision as we speak," Mr. Brodeur said.

Mr. Brodeur said the ambassadors will meet again on Thursday and that they will continue to discuss the compromise proposal.

The United States and 15 other allies say the three holdouts are undermining the one-for-all, all-for-one principle of mutual defense that is at the alliance's core.

But a German diplomat said what is at stake here is more than the defense of Turkey. He says his country and the other holdouts are telling the United States that they refuse to march in lockstep with Washington's timetable for a war against Iraq.