Washington ? As U.N. weapons inspectors moved ahead with plans to return to Iraq, the United States and Russia clashed on Tuesday over whether to take Baghdad at its word or impose a new ultimatum. “We have seen this game before,” a skeptical Colin Powell said.

The secretary of state reaffirmed Washington’s call for a tough anti-Iraq resolution by the U.N. Security Council, despite Iraq’s sudden about-face on inspections.

But Russia’s foreign minister said he saw no immediate need for new U.N. demands if the inspectors are quickly dispatched. He was backed up by Arab leaders, Moscow’s traditional allies. The “logic of war” may now be replaced by “the logic of peace,” said one.

The 15-member Security Council majority decided, despite a U.S. request for more time, to quickly schedule a meeting, possibly today, with chief weapons inspector Hans Blix to discuss renewed inspections. The Americans, supported by Britain and Colombia, wanted first to prepare a new resolution, diplomats said.

Blix then met with Iraqi representatives, after which the weapons inspection agency said talks on final arrangements for the return of inspectors would take place “and be concluded” during the week of Sept. 30 at a meeting in Vienna. Earlier Tuesday, the Iraqis said the talks would take place in 10 days.

In the Middle East, the business of preparing for war went on, as American warplanes flew under aggressive new rules over Iraq, and U.S. commanders considered basing heavy bombers closer by.

At a U.N. news conference at which Powell and Russia’s Igor Ivanov laid out conflicting views, Secretary-General Kofi Annan appealed for them to stick together on Iraq.

This is “the beginning, not an end,” he said. “We should try to maintain the unity of purpose that has emerged.”

The Security Council then went into closed-door consultations on a timetable for dealing with the fast-changing Iraq issue.

The council sent weapons inspectors into Iraq after the 1990-91 Gulf War, to ensure that President Saddam Hussein’s regime destroyed any chemical or biological weapons it possessed, and any capacity to produce those or nuclear weapons.

The inspectors left in 1998, ahead of U.S. airstrikes, amid Iraqi allegations that some were spying for the United States and countercharges that Baghdad wasn’t cooperating with the inspection teams.

The international “unity of purpose” Annan cited emerged after President Bush, in a speech to the U.N. General Assembly last Thursday, forcefully called for the Security Council to threaten action against Iraq if it did not allow the inspectors back.

If the world body didn’t act, Bush made clear, Washington would feel free to launch a military attack.

Bush’s was the opening move in what may become a high-stakes diplomatic chess game.

Iraq’s surprise reply came late Monday, in a letter to Annan in which Foreign Minister Naji Sabri said Baghdad would allow the inspectors back “without conditions” in order to “remove any doubts that Iraq still possesses weapons of mass destruction.”

On Tuesday, Annan told reporters that chief inspector Blix “is ready to move as quickly as is practicable.”

Asked when the inspectors might actually return to Baghdad, Iraqi representative Saeed Hasan replied, “It depends on Mr. Blix’s arrangements.”

The secretary-general indicated he didn’t believe any formal reauthorization is needed from the Security Council, whose previous resolutions set out specific conditions for their return.

The Bush administration late Monday had dismissed the Iraqi move as a ploy to split the Security Council. On Tuesday, Powell was equally dismissive.

“We cannot just take a one-and-a-quarter-page letter as the end of this matter,” Powell told reporters. “We have seen this game before” a reference to Iraqi delays and obstructions of past inspections.

He did not specify what Washington would seek in a new resolution a firm deadline, a threat of force or other tough elements. But he said the council should discuss an inspection plan and the “consequences” of an Iraqi failure to comply. Washington stresses the need for unrestricted access for the inspectors.

Russia’s Ivanov said it was important that Baghdad, which previously had sought an easing of anti-Iraq U.N. sanctions, had placed no preconditions on the inspectors’ return.

“Whether we can trust this letter or not, I think that only facts alone can corroborate this,” he said. “We need to bring about the speedy return of inspectors to Iraq.”

He said a new Security Council resolution is unneeded. “All the necessary resolutions, all the necessary decisions on that are” in existing council documents, he said. His government’s veto power can block any resolution it opposes.