Iran is stepping up efforts to win approval for what it says will be peaceful use of nuclear power as its top negotiator focuses on a resumption of uranium conversion with the head of the U.N. atomic monitoring agency.

Discussions Friday between hard-liner Ali Larijani and Mohamed ElBaradei (search), head of the International Atomic Energy Agency (search), are expected to deal with Iran's conversion efforts as well as a new agency report, diplomats said.

That report, being prepared by ElBaradei for the Sept. 19 meeting of the IAEA's board of governors, will disclose new details on Tehran's experiments with small amounts of plutonium, a key component of nuclear weapons, they said.

On Thursday, Larijani called for more countries to join three European nations in talks about its nuclear program, apparently hoping to bring in more sympathetic negotiators. The surprise call was part of Tehran's drive to win international approval for its program.

The talks involving France, Germany and Britain suffered a blow earlier this month when Iran rejected the Europeans' central proposal -- an offer of economic incentives in return for permanently giving up uranium development. Tehran also resumed uranium conversion at its plant in the central city of Isfahan.

The United States, which accuses Iran of seeking to develop atomic weapons, dismissed new the proposal as a "typical tactic of the Iranian government designed to change the subject." In Washington, State Department spokesman Sean McCormack (search) said the current format, involving the three EU nations, was the correct one and that Iran ought "to take the deal that is on the table."

Europe also responded coolly to Larijani's call.

Britain's Foreign Office said there was "no basis for negotiation with Iran until they respond" to an IAEA resolution adopted earlier this month that calls on Iran to suspend reprocessing activities at Isfahan. The EU countries called off a negotiating session scheduled for Aug. 31 because of the resumption of work there.

French Foreign Ministry spokesman Jean-Baptiste Mattei said France, Britain and Germany were not really alone in the talks with Tehran since they were acting on behalf of the 25-nation EU.