U.S. lawmakers are demanding President Barack Obama ensure Iran never gains the ability to build a nuclear bomb.
A total of 83 of the Senate's 100 members sent Obama a bipartisan letter on March 18 saying that "we believe that Iran has no inherent right to enrichment" and that any final deal with Iran "must prevent it from ever having a uranium or plutonium path to a nuclear bomb."
A total of 394 of the House's current 432 members wrote a similar letter asking Obama to press for a deal in which Iran would not be able to build or buy a nuclear weapon.
The letters come as Iran and world powers hold talks in Vienna aimed at reaching a long-term settlement to the Iran nuclear crisis.
Based on reporting by AFP and Reuters