White House warns senate to stay out of Iran negotiations
U.S. Senator Bob Corker (R-TN) talks to reporters as he arrives for the weekly Republican caucus policy luncheons at the U.S. Capitol in Washington, March 10, 2015. In a letter to Corker released Saturday, the White House warned the Senate to stay out of negotiations with Iran over its nuclear program. REUTERS/Jonathan Ernst

The White House has issued a strongly worded warning to the Senate not to interfere with the administration's attempts to negotiate a deal with Iran over its controversial nuclear program.

A letter, released to the media Saturday night, from White House Chief of Staff Denis McDonough to Senate Foreign Relations Committee Chairman Bob Corker, said that a bill Corker is drafting may tie the administration's hands and prevent a deal from being agreed.

Corker is working on legislation that would force the administration to submit any deal reached with Iran for a vote by Congress. The White House earlier threatened to veto such a measure, CNN reported.

"The legislation you have introduced in the Senate goes well beyond ensuring that Congress has a role to play in any deal with Iran. Instead, the legislation would potentially prevent any deal from succeeding by suggesting that Congress must vote to 'approve' any deal and by removing existing sanctions waiver authorities that have already been granted to the President," McDonough wrote.

While only Congress ultimately has the power to rescind U.S. sanctions on Iran, the president has the power to unilaterally suspend them through waivers. Corker's bill would make this process far more complex, possibly leaving the administration unable to meet commitments under a future agreement if congress did not approve, according to a Huffington Post report.

"The Administration's request to the Congress is simple: let us complete the negotiations before the Congress acts on legislation," wrote McDonough. "We understand that Congress will make its own determinations about how to respond, but we do not believe that the country's interests are served by congressional attempts to weigh in prematurely on this sensitive and consequential ongoing international negotiation aimed at achieving a goal that we all share: using diplomacy to prevent Iran from developing a nuclear weapon."

U.S. Secretary of State John Kerry is due in Geneva Sunday, for last-ditch talks to agree a framework deal with Iran over its nuclear program. Iran insists that its nuclear program is for peaceful purposes only, but the U.S. and other Western countries are concerned that the country is trying to develop nuclear weapons.

Congress has been keen to involve itself in the negotiations with Iran over its nuclear program. An open letter to the Iranian leadership signed by 47 Republican senators warned earlier this month that a future U.S. president may nullify any agreement.

In addition, House Speaker John Boehner invited Israeli Prime Minister Benjamin Netanyahu to address Congress, against the wishes of the White House, where he warned that the deal being negotiated would allow Iran to develop nuclear weapons.