Mitch McConnell
Mitch McConnellReuters

Senate Majority Leader Mitch McConnell defended on Sunday the letter he and 46 other Republican senators sent to Iran's leaders on Monday, in which they informed Iranian leaders that any deal they sign with the Obama Administration would serve only as an executive agreement that could be revoked by a future president.

President Barack Obama and State John Kerry have claimed that the letter is “unprecedented” and that it undermines negotiations with the Islamic republic. But McConnell insisted, in an interview with CNN, that the Administration was exhibiting a "good case of selective outrage" and noted that, as a senator, Kerry met with Nicaraguan president Daniel Ortega, during the Sandinista conflict between Nicaragua and the US, under then-President Ronald Reagan.

McConnell also pointed out that former Senate Majority Leader Robert Byrd (D-W.Va.) flew to Moscow in 1979 to tell Russian officials that the Senate could block the Salt II nuclear treaty, which was then being discussed.

“I don’t think it was a mistake,” he said about the letter. “It’s no more unusual than Robert Byrd going to Moscow or John Kerry going to Managua.”

"The President is about to make what we believe is a very bad deal. He clearly doesn't want Congress involved at all. And we're worried about it," McConnell told CNN's Dana Bach on "State of the Union.”

"The president would like to keep us out of it. We know that."

"All of this is a distraction away from the point here," McConnell said, repeating that the Obama administration is about to sign "a very bad deal with one of the worst regimes in the world."

"It specifically inserts itself directly to the leader of another country saying, 'Don't negotiate with these guys because we're going to change this,'" Kerry said in the interview. "It is incorrect because they cannot change an executive agreement."

McConnell said that the Senate will act on at least one of two bills after the deadline for negotiators in Geneva to reach a preliminary agreement, two weeks from now: the first would require the administration to receive the approval of Congress for the deal. The second would re-impose tougher sanctions on Iran.