A leading Republican critic of President Barack Obama’s foreign policy is pushing new sanctions against Iran over its nuclear program, unswayed by a White House veto threat and lobbying by Britain’s leader.

Sen. Lindsey Graham of South Carolina did say Sunday that he would be willing to set aside his efforts if Obama would submit any agreement with Tehran to Congress for lawmakers to approve or reject.

An Obama adviser scoffed at the idea as an infringement on presidential authority.

The new GOP-led Congress has picked an early foreign policy fight with the president, with the Senate Banking, Housing and Urban Affairs Committee holding a hearing Tuesday on possible new penalties against Tehran.

The U.S. and its partners in the negotiations are trying to reach a framework agreement with Iran by March and hoping to complete a longer-term deal by July that would limit Iran’s ability to produce a nuclear weapon.

Iran says its program is for peaceful purposes.

Secretary of State John Kerry has stepped up talks with Iran’s foreign minister, Javad Zarif, and they may hold further discussions this week when both are expected to attend the World Economic Forum in Switzerland.

Graham described congressional efforts as signaling to the Iranians that “we would like a political negotiation, a diplomatic solution. But please understand in Iran that the Congress is intent on reapplying sanctions if you walk away from the negotiating table and if you cheat,” Graham said. “I don’t think that’s a disruptive message.”

As an alternative, he said that if Obama “thinks sanctions is disruptive to a good outcome, I’m willing to forgo that vote with the understanding that any deal he negotiates will come to the Congress for our approval or disapproval as a check and balance.”

White House adviser Dan Pfeiffer contended that Graham “would like to make all the foreign policy decisions of the United States and be commander in chief. … It’s the president’s authority.”

Pfeiffer added, “It does not make any sense for Congress to scuttle that deal … because that would put America in a bad place, not just in dealing with Iran but with the world.”

The White House will continue to consult with Congress, he said.

Obama said at a news conference Friday that imposing new sanctions probably would doom the nuclear negotiations and heighten prospects of a military showdown. “Just hold your fire,” the president pleaded to Congress, while also issuing the veto threat.

British Prime Minister David Cameron, who was visiting Washington last week, said he was calling senators to convey the message that new penalties would hurt international unity.

Graham and Pfeiffer spoke on NBC’s “Meet the Press.”

(AP)