Secretary of State Colin Powell's insistence on traditional diplomacy to disarm Iraq has run into a stone wall in the United Nations, dealing a blow to his moderate approach within the hard-line Bush administration.

With the U.N. Security Council due to take up a U.S.-British-Spanish resolution next week to authorize force against Iraq, Powell was trying anew Thursday to convince skeptical governments that only such a step, not more inspections, would do the job.

The odds against him were long. Failure would confirm the view of Vice President Dick Cheney and Defense Secretary Donald H. Rumsfeld that turning to the United Nations would only produce a stalemate and delay disarming Iraq.

Powell prevailed in his advice to President Bush, although the president questioned U.N. relevance as he kicked off the diplomatic campaign in a speech last September.

Through it all, Powell has been the administration's point man, cajoling and appealing to reluctant allies such as France and Germany and laying out the U.S. case to the council with intelligence data that failed to persuade the skeptics.

In the process, the United States and its allies have been split over Iraq to an extent unprecedented in the past half-century.

Watching this play out, Iraqi President Saddam Hussein has cooperated just enough with the U.N. weapons inspectors to convince most council members that that the prescription for disarmament was more inspections, not war.

President Bush continued the diplomatic push by phone Thursday, calling Vaclav Klaus, the new president of the Czech Republic, and Portuguese Prime Minister Jose Durao Barroso, both of whom have supported the U.S. position. Bush also spoke with Mexican President Vicente Fox, but there was no sign he won an assurance of Mexico's support in the Security Council.

He also spoke with Russian President Vladimir Putin, who has opposed the resolution, and they agreed to speak again.

Powell, before heading to New York for talks with Security Council envoys, told a Senate subcommittee that the Iraqi threat must be dealt with now.

"The moment we find ourselves in is a critical moment. We are being tested, the Security Council of the United Nations and the international community are being tested," Powell said.

But Senate Democratic leader Tom Daschle said the administration had brought on an "extraordinary disintegration" of support from other nations by rushing toward war. He said the administration should continue reaching out to other countries.

"There is still a chance that a worldwide international coalition effort can be achieved," said Daschle, D-S.D.,

Sen. Carl Levin, D-Mich., the top Democrat on the Senate Armed Services Committee, said U.S. intelligence agencies had shared with weapons inspectors information about only a small fraction of Iraq's suspicious sites.

"If we have not shared the suspect sites, we undermine our own case," Levin said.

In New York, Powell met with British Foreign Secretary Jack Straw, who is trying to save the resolution with some tinkering that would give Iraq a short time to comply with disarmament demands.

Powell talked to Foreign Minister Sheik Hamad bin Jassem Al Thani of Qatar, whose Persian Gulf country helps the United States by housing the Central Command. He also met with Straw and Spanish Foreign Minister Ana Palacio to consider whether to revise the resolution, and then with Foreign Ministers Joschka Fischer of Germany and Dominique de Villepin of France.

Powell's spokesman later characterized the talks as "good, extensive discussions" that were to continue Friday morning. There could "possible changes in the text" of a resolution, Richard Boucher said in a statement.

"They were seeking a resolution that can obtain maximum support while making it clear that the council stands by the requirement to disarm immediately," Boucher said.

Rumsfeld questioned whether France or Russia would follow through on threats to veto the latest U.S.-backed resolution.

"People say a lot of things that they ultimately don't do, and whether someone would veto it, I just don't know," Rumsfeld told CNBC. He said last November's resolution on Iraq clearly anticipated military action upon continued defiance by Iraq.

"Pretty clear language, and they all knew what they were voting for. These are people who can read," Rumsfeld said.

Powell was to see Russian Foreign Minister Igor Ivanov and others on Friday, and attend the council meeting to hear weapons inspector Hans Blix's report on searches in Iraq.

Bush's national security adviser, Condoleezza Rice, met with about 20 Iraqi expatriates, some from a women's group. White House officials stressed that the meeting was not part of an effort to set up a postwar government in Iraq, but rather to hear their stories about suffering under Saddam.

But Saman Shali, executive vice president of the Kurdish National Congress of North America, said Rice told the expatriates that the United States envisions a coalition of various ethnic and political groups to run a postwar Iraq.

On Capitol Hill, Pentagon officials for the first time gave cost estimates for the buildup for a possible war and occupying Iraq afterward: $47 billion to $67 billion through Sept. 30.

The estimates came from the civilian heads of the Army, Navy and Air Force, who said they could not estimate the costs of combat, either in dollars or lives.