Washington ? The Bush administration said Wednesday a proposal by Iran for nuclear negotiations falls short of U.N. demands that it cease uranium enrichment, and the U.S. began plotting unspecified “next moves” with other governments.

At the same time, Iran contended it had offered “positive and clear signals” to resolve the dispute over its nuclear program.

Efforts by the U.S. and other nations could lead to U.N. sanctions against Iran unless it reverses course and agrees to a verifiable halt to enrichment activities that can be central to making nuclear weapons.

France took a firm and quick stand on Iran’s proposal. Foreign Minister Philippe Douste-Blazy said the Iranians must suspend uranium enrichment if they want to return to negotiations.

However, Russia’s foreign ministry, evidently ambivalent, said it would continue to seek a negotiated solution. And China appealed for dialogue, urging “constructive measures” by Iran and patience from the United States and its allies.

The State Department, in a terse statement, acknowledged that Iran considered its proposal to be a serious one. “We will review it,” the statement said in what appeared to be a conciliatory gesture to a government it regularly denounces as a sponsor of terror.

But the statement went on to say that Iran’s response to a joint offer of U.S. and European trade and other benefits if the enrichment program was halted “falls short of the conditions set by the Security Council” – full and verifiable suspension of all uranium-enrichment activity.

“We are consulting closely, including with other members of the Security Council, on next steps,” it said. The United Nations has set a deadline of Aug. 31 for a formal reply by Tehran.

President Bush met with Secretary of State Condoleezza Rice at the White House and then discussed Iran’s proposal in a telephone call with U.N. Secretary-General Kofi Annan.

The call was initiated by Annan, White House spokeswoman Dana Perino said.

The administration has cautioned Iran that it will seek sanctions in the Security Council if Tehran does not step enriching uranium.

By not rejecting Iran’s proposal outright, the administration indicated there may be a basis for dealing with long-held concerns that Tehran is developing nuclear weapons, an allegation the Iranians deny.