Two U.S. senators have introduced a bill in the Senate imposing sanctions should talks with Iran on its nuclear program collapse after June 30.
Mark Kirk (Republican-Illinois) and Robert Menendez (Democrat-New Jersey) introduced the draft legislation on January 28.
The bill has 16 co-sponsors from both parties.
But Menendez and the six other Democratic co-sponsors wrote a letter to President Barack Obama on January 27 saying they would not support a vote on the bill until March 24, in order to give a chance for ongoing diplomatic talks between and Iran and six world powers -- Britain, France, China, Russia, Germany, the United States.
The senators said they would support a vote on the legislation after March 24 if negotiators fail to reach a political framework for an agreement curbing Tehran's nuclear program, which Western governments fear is aimed at developing atomic weapons, in exchange for sanctions relief.