Senators warn Iran nuke deal may expire when Obama leaves

Nearly half of the US Senate wrote an open letter to the Iranian leadership Monday, warning that any deal reached between Washington and Tehran during the ongoing nuclear talks won’t remain in effect after President Barack Obama leaves office.

The letter, signed by 47 Republican senators, is the latest effort to pressure the Obama administration into granting Congress some oversight over the nuclear negotiations and emerging agreement, Bloomberg reported Monday.

“It has come to our attention while observing your nuclear negotiations with our government that you may not fully understand our constitutional system … Anything not approved by Congress is a mere executive agreement,” the lawmakers wrote.

“The next president could revoke such an executive agreement with the stroke of a pen and future Congresses could modify the terms of the agreement at any time.”

By calling attention to the short-term nature of an agreement without congressional approval, the Republican leadership is apparently hoping to prompt Tehran to reconsider moving forward with the next round of talks set to begin March 15.

Among the signatories were 2016 Republican presidential contenders Marco Rubio, Ted Cruz and Rand Paul.

“Iran’s ayatollahs need to know before agreeing to any nuclear deal that…any unilateral executive agreement is one they accept at their own peril,” freshman Senator Tom Cotton told the paper.

The negotiations have become a campaign issue in the Republican 2016 presidential campaign, with many prominent GOP lawmakers publicly criticizing the emerging deal for not being aggressive enough in preventing Iran from obtaining a nuclear bomb.

Despite Obama’s reassurances that without a guarantee that Iran is unable to obtain nuclear weapons the US would walk away from the negotiations, US lawmakers are trying to pass legislation that would allow the Senate to override Obama on a final approval of the terms.

Secretary of State John Kerry, left, and Iranian Foreign Minister Mohammad Javad Zarif prepare to take their seats for a new round of nuclear negotiations in Montreux, Switzerland on March 2, 2015. (photo credit: AFP/POOL /EVAN VUCCI)

The general outline of the proposed deal reportedly includes regular inspections, a freeze on sensitive nuclear activity for at least 10 years and a cap on the number of centrifuges allowed and limited uranium enrichment.

The US-led negotiations are pressed to reach a framework deal before a deadline at the end of March. A final agreement is supposed to be signed by the end of June.

Congress is also expected to consider legislation later this month that would call for increased sanctions on Iran if a deal fails to materialize. Obama has vowed to oppose any such moves.

Negotiators on both sides have expressed cautious optimism that a deal is within reach.