WASHINGTON — US Secretary of State John Kerry warned Friday that should Congress vote against the Iranian nuclear deal signed last week in Vienna, Israel could find itself more isolated in the international arena and “more blamed.”

“I fear that what could happen is that, if Congress were to overturn it, our friends in Israel could actually wind up being more isolated. And more blamed. And we would lose Europe and China and Russia with respect to whatever military action we might have to take. Because we will have turned our backs on a very legitimate program that allows us to put their program to the test over the next few years,” Kerry told an audience at the Council of Foreign Relations in New York.

The statement was promptly rejected by the former Israeli ambassador to the United States Michael Oren, now a member of the centrist Kulanu party.

“If American legislators reject the nuclear deal, they will do so exclusively on the basis of US interests. The threat of the secretary of state who, in the past, warned that Israel was in danger of becoming an apartheid state, cannot deter us from fulfilling our national duty to oppose this dangerous deal,” Oren said in a statement.

Michael Oren. (Photo by Nati Shohat/Flash90)

Michael Oren. (Photo by Nati Shohat/Flash90)

Earlier Friday, Kerry warned that any future Israeli military action against Iran over its nuclear program would be an “enormous mistake.”

Iran and the US-led P5+1 world powers signed a nuclear deal last week that would see Iran curbing its nuclear program in exchange for the lifting of international sanctions. The agreement was met with fierce opposition by Israel, Saudi Arabia and other countries that maintain the deal doesn’t go far enough to prevent Iran from developing a nuclear weapon.

In Israel, politicians across the spectrum slammed the deal as soon as it was announced.

Opposition leader Isaac Herzog, head of the Zionist Union party, said he would work with Prime Minister Benjamin Netanyahu’s ruling coalition to thwart the Iran nuclear deal.

“Now Iran is out of the cage and will become a regional tiger,” Herzog said last week, calling the agreement “a complex challenge that mandates cooperation on understanding the threat and on finding solutions.”

Yesh Atid chairman Yair Lapid, who also sits in the opposition, said the Iran deal was the country’s biggest foreign policy failure ever, and blamed Netanyahu for mishandling the affair.

Netanyahu earlier this week urged US lawmakers to combat Iranian aggression by rejecting the nuclear deal.

The agreement now goes to Congress which started a 60-day review of the deal and is expected to vote on it by September 17. Congress can pass a motion of disapproval, which President Barack Obama can veto. An override of the veto requires two-thirds approval in both the House and Senate.

Kerry said Friday it would be embarrassing to him and a blow to US credibility on the world stage if Congress rejects the deal.

It would be a “repudiation of President Obama’s initiative and a statement that when the executive department negotiates, it doesn’t mean anything anymore because we have 535 secretaries of state,” Kerry said, referring to the number of members of the House and Senate.

“Do you think the ayatollah is going to come back to the table if Congress refuses this and negotiate again?” he asked.

“Do you think that they’re going to sit there and other people in the world are going to say, ‘Hey, let’s go negotiate with the United States, they have 535 secretaries of state’?,” Kerry said.

“I mean please. I would be embarrassed to try to go out. What am I going to say to people after this as secretary of state. ‘Come negotiate with us.’ ‘Oh, can you deliver?’ Please.”

Kerry defended the nuclear deal, saying it was the only alternative to military action and must be tested if diplomacy is to succeed.

In a reprise of his testimony Thursday before the Senate Foreign Relations Committee, Kerry said the agreement is the best way to prevent Iran from developing an atomic weapon. If Congress rejects the deal, he said Iranian hardliners would speed ahead with their nuclear program and the international sanctions regime would collapse.

He said there is more chance of a nuclear arms race in the Middle East without the recently negotiated deal.

Kerry also revealed Friday that the Bush administration offered a far more generous package than the current nuke deal in its efforts to thwart Iran’s nuclear program, but Tehran rejected it.

The US secretary of state will later Friday meet with the leaders of the American Jewish Committee and the Conference of Presidents of Major American Jewish Organizations to discuss the deal.

Ricky Ben-David, AP and AFP contributed to this report.