Britain and Canada took the lead Tuesday in trying to break the diplomatic impasse over how much time Saddam Hussein should be given to prove he has disposed of his weapons of mass destruction.

Six countries that represent the key to a U.S. victory in the Security Council proposed a 45-day reprieve for Iraq. The Bush administration said it was willing to listen but wants a far shorter deadline. It said a vote will come by the end of this week, regardless.

As America kept its war plans on hold, with hundreds of thousands of troops waiting for orders to strike, diplomats grappled over the details of how Iraq might avoid bloodshed.

Tuesday was supposed to be showdown day, with a Security Council vote on an British-American resolution setting a March 17 deadline for disarmament. But the allies backed off. Without the nine votes they need, and with France and Russia pledging vetoes, they pulled their plan off the table.

The question of the day: What comes next, and when?

The Bush administration was dismissive of the proposal by Angola, Cameroon, Chile, Guinea, Mexico, and Pakistan to extend the deadline 45 days. "A nonstarter," said White House spokesman Ari Fleischer.

"On this matter, the American people are becoming increasingly impatient with the U.N.," he said.

But it was not clear that those nations and the veto-holding permanent members would be willing to accept something less.

The substance of the British proposal was not made public, and there were indications it was still on the drawing board.

Generally, Saddam would have 10 days to prove Iraq has taken a "strategic decision" to disarm, which could be done with a series of tests or "benchmarks," council diplomats said. A close aide to Chilean President Richardo Lagos called it a "checklist of about 12 items."

If that happens, a second phase would begin with more time to verify Iraq's full disarmament, they said, speaking on condition of anonymity.

But a senior White House official, speaking on condition of anonymity, said the time frame being circulated was shorter.

"The United Kingdom is in a negotiation and it's prepared to look at timelines and tests together," Britain's U.N. Ambassador Jeremy Greenstock said in a televised interview. "But I'm pretty sure we're talking about action in March. Don't look beyond March."

A U.S. official, speaking on condition of anonymity, said Washington still wanted a short deadline of 7 to 10 days from the date of the resolution's passage.

"A week is no good, it's the same as 10 days," said Angola's U.N. Ambassador Ismael Gaspar Martins. "We'd prefer the 45 days as we have requested. If it's too long let's see what is acceptable."

Chile's Lagos said Monday that he can't support the current U.S. resolution. A close aide said Tuesday that Lagos thinks the March 17 deadline is much too short and and while he hasn't mentioned a new deadline, there has been talk of "two to three weeks."

France said Tuesday it was "open to dialogue" but will not budge on the fundamentals it has championed since the Iraq crisis started.

A day after threatening to veto any U.N. resolution authorizing force against Baghdad, Foreign Ministry spokesman Francois Rivasseau said France cannot cross a "red line" by allowing any resolution that contains an ultimatum or the automatic use of force against Baghdad.

Fleischer insisted the resolution would be put to a vote this week. But another senior administration official cast doubt on this, saying State Department officials are trying to convince the White House that it would be better to postpone the vote and avert a veto.

Secretary of Defense Donald H. Rumsfeld, at a Pentagon news conference, said the delay was having little effect on the American forces. "I wouldn't think that it would make an enormous difference to this department in terms of what they're doing up there," he said.

Rumsfeld also caused consternation in London by suggesting that America's staunchest ally might not participate in a war with Iraq because of opposition in Britain.

"Until we know what the resolution is, we won't know the answer as to what their role will be," he said.

But British officials said they had every intention of keeping their promise to fight Iraq, if necessary. And the Pentagon later issued a statement in which Rumsfeld said he had "every reason to believe there will be a significant military contribution from the United Kingdom."

British Prime Minister Tony Blair is under intense pressure at home to get U.N. backing for any fresh military action.

"The United Kingdom will only act within international law and we're looking for the United Nations to remain in control of this huge issue," said Greenstock, the British ambassador. "We're going to go on talking until we find a way forward for the Security Council together."

But he said in the interview that "if military action is the only way to complete disarmament of Iraq, then my prime minister has made it absolutely clear that he will go that route."

While London worked on its proposals, others were preparing their own compromises.

Canada, which isn't a Security Council member, revised an earlier compromise proposal that had drawn wide interest. Canada called for a new resolution to authorize force and would set a three-week deadline for Iraq to show it is cooperating fully with U.N. disarmament demands.

At the same time, Canada's U.N. Ambassador Paul Heinbecker said chief U.N. weapons inspector Hans Blix should present a list of key remaining disarmament tasks within a week and stipulate steps and a timeline for Iraq to implement them. If Baghdad is found to be cooperating, new deadlines could be set until all U.N. disarmament goals are met.

"We are convinced that Iraq is substantially contained and that, if it cooperates, can be disarmed without a shot being fired," Heinbecker said.

The Security Council heard speeches from 28 nations on the first day of a two-day open meeting on the Iraq crisis at the at the request of the Non-Aligned Movement, which represents 116 mainly developing countries. Most are opposed to a war.

The meeting had the effect of putting off any vote until Thursday, at least, as America and its backers would have to give 24 hours notice before a vote was held.

Iraq's U.N. Ambassador Mohammed Al-Douri was the leadoff speaker, accusing the United States of trying "to lay their hand on our oil, to control the region, to redraw our borders."

"Iraq has taken the strategic decision to rid itself of weapons of mass destruction ... and reiterates its readiness to cooperate," he said. "We will convincingly respond to anyone who has any doubts about Iraq's cooperation."