Intensive U.N. talks over Iraq policy broke off today, setting the stage for an American effort to break the impasse by forcing the Security Council to vote next week on whether to send U.N. weapons inspectors back to Iraq for the first time in a year.

Calling a vote would bring to a head months of negotiations and force Russia, China and France to either accept British and American terms for the resumption of weapons inspections or lose an opportunity to ease the economic sanctions on Baghdad, Western diplomats said.

"The United States would like to have a vote by the end of next week," said Peter Burleigh, the deputy U.S. representative to the United Nations. But he said a final decision on whether to bring the proposal before the Security Council would be made in the next few days, after high-level contacts between leaders in Moscow, Washington, London, Beijing and Paris.

The American and British effort to move the negotiations into an endgame comes as Russia's ambassador to the United Nations, Sergei Lavrov, is set to travel to Moscow next week to meet with Iraq's deputy prime minister, Tariq Aziz. So far, Iraq has rejected all entreaties to allow the inspectors to return.

The United States and Britain, which will assume the council's rotating presidency in December, want the negotiations to wrap up by Dec. 4, when the council meets to decide whether to renew the "oil-for-food" program that permits Iraq to sell $5.2 billion worth of oil every six months to enable it to buy food and medicine for its people.

The five permanent members of the 15-nation Security Council--the United States, China, Russia, France and Britain--all favor a resumption of weapons inspections but have been at loggerheads on the terms for sending inspectors back to Iraq.

"We have come a long way over the past few months, and have reached agreement on most of the points of difference," British Foreign Secretary Robin Cook said Wednesday.

Lavrov, however, told his counterparts in New York this week that Russia is prepared to veto the resolution as it stands, according to a diplomat involved in the talks. Although France has moved closer to the American and British position in recent weeks, it has said it will not endorse a resolution that lacks Russia's approval.

"We are finishing the chess game and beginning the poker game," said a diplomat involved in the talks. "And everybody thinks everybody else is bluffing."

U.S. Undersecretary of State Thomas Pickering held bilateral talks with Lavrov in New York on Tuesday, and Moscow has signaled that it might be willing to show flexibility on Iraq in exchange for less criticism from Washington of its Chechnya policy. But fundamental differences remain.

Russia, France and China want the sanctions on Iraq, which were imposed after it invaded Kuwait in 1990, to be eased quickly if Saddam Hussein's government agrees to cooperate with the weapons inspectors. The United States and Britain insist that the sanctions must remain in place for a "test period" to determine whether Iraq really is cooperating with the inspections and has abandoned all of its chemical, biological and nuclear weapons programs.

Effectively, the U.S.-backed proposal would put off the politically difficult decision of suspending the sanctions on Iraq until after the presidential election in November 2000. "Russia, France and China say the test period is currently too long," said one diplomat involved in the negotiations. "The Russians want a specific date for action."

The United States has, however, made at least one concession in the negotiations: Instead of insisting on complete disarmament, the United States will settle for assurances that the "key" disarmament tasks have been resolved before sanctions are eased, diplomats said.

CAPTION: Sergei Lavrov, Russia's ambassador to the United Nations, is scheduled to meet with Tariq Aziz of Iraq next week.