The United States will reject any proposal that will not allow Iran to stop domestic nuclear enrichment and reprocessing activities, the New York Times said ina report on Tuesday, citing a senior U.S. official.

"The United States will not support any halfway measures ... That means full suspension of all nuclear activities, and a return to negotiations on that basis," Nicholas Burns, U.S. under secretary of state for political affairs, was quoted by the reportas saying.

According to the report, Russia proposed that Iran would temporarily suspend all uranium enrichment activities at its facility at Natanz but then be allowed to do what Russia describesas "limited research activities" in Iran's uranium enrichment program.

The proposal is a reversal of its previous stance and seemed motivated by its determination to protect Iran from judgment by the United Nations Security Council, the report said.

The reports of the proposal prompted Secretary of State Condoleezza Rice to call Mohamed ElBaradei, the director of the International Atomic Energy Agency, and said "the United States cannot support this."

Rice told ElBaradei that Washington wanted to see Iran's case before the United Nations Security Council as soon as this week's agency board meeting was over.

The United States has insisted on referring Iran's nuclear issue to the United Nations Security Council for possible sanctions.