VIENNA, Austria  —  The United States is ready to meet with Iran and other nations for talks on Tehran's nuclear ambitions if the Islamic republic gives up uranium enrichment, diplomats said Wednesday.

But the diplomats, who requested anonymity because the information was confidential, said Washington would only do so if Russia and China agreed to back U.N. Security Council sanctions against Iran if it remains defiant on the enrichment issue.

One of the diplomats told The Associated Press that the Bush administration was planning to make an official announcement on Washington's conditional readiness to join in such talks later in the day.

The development is significant because the United States has had no official direct talks with the Iranians since the two countries cut diplomatic ties following the occupation of the U.S. Embassy in Tehran by radicals in 1979.

However, Tehran has repeatedly said it will not stop enriching uranium, and China and Russia have both said they oppose the use of sanctions against Iran.