Challenged by skeptics at home and abroad, the Bush administration plans to make public next week details about Iraq's weapons programs that have not been given to U.N. inspectors.

Secretary of State Colin Powell will make the presentation at the United Nations next Wednesday and meet with the foreign ministers of most if not all 14 other members of the U.N. Security Council, a senior U.S. official said.

In determining what evidence to present, which could include photographs, the administration's goal is to convince other nations and the American public that Iraq has concealed weapons of mass destruction.

But a photograph that is meaningful to intelligence officers may appear to an untrained observer as simply a bunch of rooftops, said the official, speaking on condition of anonymity.

On a new U.N. resolution, the administration takes the position that one is not necessary to use force against Iraq in light of the warning of serious consequences for failure to disarm in an earlier resolution.

But if a fresh resolution would help other governments make the case to their public for using force the Bush administration would consider it, this official said.

The decision will be taken after Powell consults with the other foreign ministers, the official said.

White House spokesman Ari Fleischer said Wednesday that "we're nearing the final phase," and that only a narrow "diplomatic window" remained open. President Bush has meetings this week with prime ministers Silvio Berlusconi of Italy and Tony Blair of Britain.

On Wednesday, White House press secretary Ari Fleischer declined to elaborate on what evidence will be furnished, although he did say Powell would "connect the dots."

Bush already sees "a Mount Everest of information. Making Mount Everest is not necessary," Fleischer said.

Meanwhile, Powell and other Cabinet officers were taking the U.S. case against Iraq to members of Congress.

U.N. inspectors reported this week that Iraq hasn't provided evidence it dismantled chemical and biological weapons programs and has failed to fully cooperate in the inspection process. The administration says that bolsters its case that Iraq is not living up to its obligations under U.N. resolutions. But some U.S. allies say that isn't enough to justify war and the United States should provide evidence that Iraq still possesses banned weapons.

The administration has been reluctant to do so, saying that could force the disclosure of intelligence sources and methods. But it is hearing from all sides that it has not clinched the case.