Kerry: Congress cannot modify any Iran-US nuclear agreement
Despite threats made by Republican senators in a letter sent to the Iranian leadership, US secretary of state says Congress does not have the power to modify any future agreement with Iran.
In congressional testimony, Kerry said he responded with "utter disbelief" at an open letter signed by 47 Republican senators that threatened to undo any nuclear agreement reached between Tehran and Washington.
"It is incorrect when (the letter) says that Congress can actually modify the terms of an agreement at any time. That is flat wrong," Kerry told the Senate Foreign Relations Committee, which does not include Senator Tom Cotton, the Republican from Arkansas who wrote the letter.
The White House slammed the letter as "reckless" and "irresponsible," warning that it interfered with efforts to negotiate with the Iranians.
The negotiations, which resume in Lausanne, Switzerland, next week led by Kerry, are at a critical juncture as the sides try to meet an end of March target for an interim deal, with a final deal in June that would ease crippling sanctions against Iran's economy.
The letter was an unusual intervention by lawmakers into US foreign policy. The US Constitution divides foreign policy between the president and Congress.
Vice President also spoke out against the letter on Tuesday, saying: "The decision to undercut our president and circumvent our constitutional system offends me as a matter of principle."
In an open letter sent Monday to the leaders of Iran, the Republican senators warned that any nuclear deal the Iranians cut with Obama could expire the day he leaves the White House. The letter was an aggressive attempt to make it more difficult for Obama and five world powers to strike an initial agreement by the end of March to limit Iran's nuclear program, which Tehran insists is for peaceful purposes.
Republicans worry that Iran is not negotiating in good faith and that a deal would be insufficient and unenforceable, allowing Iran to eventually become a nuclear-armed state. They have made a series of proposals to undercut or block it - from requiring Senate approval for any agreement to ordering new penalty sanctions against Iran or even making a pre-emptive declaration of war.
The Republicans' move came just days after Israeli Prime Minister Benjamin Netanyahu spoke to a joint meeting of Congress at Republican House Speaker John Boehner's invitation. In his address, Netanyahu bluntly warned the United States that a deal would pave Iran's path to a nuclear bomb.
Reuters and the Associated Press contributed to this report.
