In the House, more than 150 Democrats, including Pelosi, signed a letter in May strongly supporting the nuclear negotiations.

Bob Corker is chairman of the Senate Foreign Relations Committee.

“Because of this deal, Iran will remove two-thirds of its installed centrifuges – the machines necessary to produce highly enriched uranium for a bomb – and store them under constant worldwide supervision”.

Other leading Republicans went much further in their criticism.

“Without the passage of our bill, Congress would have had no role in reviewing and voting on an agreement”, added Corker.

Israeli Prime Minister Benjamin Netanyahu said in a statement Tuesday that the deal is a “bad mistake of historic proportions” and would enable Iran to “continue to pursue its aggression and terror in the region”.

The deal now faces skeptical members of Congress, who have 60 days to debate it publicly. Because of this deal, that stockpile will be reduced to a fraction of what would be required for a single weapon.

The nuclear-related sanctions hurt the Iranian economy, which was denied foreign credits and part of oil revenues due to Western restrictions.

But in a bid to allay concerns, Natanyahu said, “I say to all the leaders in Israel – now is the time to put aside petty politics and unite for…Israel’s future and security”. “Congress has a responsibility to carefully review the agreement to ensure it is in the best interests of our national security”.

The entire Iran deal still has to be approved by Congress. A vote on that will likely happen in September. Aides said they want to decide on a course of action this month. Only if lawmakers were to build a veto-proof majority behind new legislation enacting new sanctions or preventing Obama from suspending existing ones, the administration would be prevented from living up to the accord. Those efforts are expected to intensify now with a deal.

Tom Cotton was on MSNBC early Tuesday morning to blast the deal that the United States and five world powers have reached with Iran to limit the country’s nuclear program in exchange for sanctions relief.

As recently as late Monday, sticking points remained in the Vienna talks, including Iran’s insistence on the lifting of an embargo on the sale of conventional weapons and missiles, multiple sources said.

Iran’s historic nuclear deal may ease hostility with the West that has fueled Middle East tensions for decades, but it is unlikely to change the course of conflicts where Tehran and Washington are both awkward allies and enemies. There is no guarantee a Republican president, in particular, would do so.