In opening remarks at a House Foreign Affairs Committee hearing July 28, Secretary of State John F. Kerry warned that discussion of the deal on Iran's nuclear program had been distorted in public discourse. (AP)

Three Cabinet secretaries on Tuesday defended the Iran nuclear agreement before hostile House members who heaped scorn on the deal, on Iran and on the negotiators.

Secretary of State John F. Kerry, Energy Secretary Ernest Moniz and Treasury Secretary Jack Lew spent four hours testifying before the House Foreign Affairs Committee. As happened last week when the three appeared before the Senate Foreign Relations Committee, the hearing was broadcast live on state television in Iran.

Kerry, who made dozens of trips to European and Middle Eastern capitals over the past 18 months negotiating the agreement announced July 14, told Congress that a congressional rejection could prompt Iran to expand its nuclear program while also killing international sanctions against the country.

“You’ll not only be giving Iran a free pass to double the pace of its uranium enrichment, to build a heavy-water reactor, to install new and more efficient centrifuges, but they will do it all without the unprecedented inspection and transparency measures that we have secured,” Kerry said. “Everything that we have tried to prevent will now happen.”

Many of the lawmakers, including Democrats whom the White House is counting on to prevent any override of a presidential veto, expressed concern that Iran would be free to pursue a nuclear weapon after restrictions in the deal expire.

Secretary of State John F. Kerry defended the recent Iran nuclear deal at a Senate committee hearing last week where Republican senators expressed displeasure over the agreement. (Sarah Parnass/The Washington Post)

“I have a fundamental concern that 15 years from now, Iran will essentially be off the hook,” said Rep. Eliot L. Engel (N.Y.), the ranking Democrat on the committee.

Kerry said that the restrictions would ease off gradually.

“There’s not some sudden break-off at the end of 15 years; there are remarkable restraints,” said Kerry, adding that rejecting the agreement would hasten a nuclear-armed Iran.

“If you walk away, year 15 or 20 starts tomorrow, and without any of the long-term access and verification safeguards we have put in place,” he said. “What is the alternative? What are you going to do when Iran does start to enrich, which they will feel they have a right to if we walk away?”

The hearings are part of a 60-day review process mandated by law. The GOP-led Congress is expected to vote to reject the agreement, but President Obama has said he will veto any legislation that would block the deal’s implementation.

Many Republicans on the committee were openly disdainful of the negotiators, including the men in front of them.

“America got played like a five-string quartet,” said Rep. Lee Zeldin (R-N.Y.). “Mr. Secretary, a lot of Americans have fought and died to make our country the greatest nation in the world. And you, sir, respectfully, you don’t have the power to surrender our greatness.”

Secretary of State John F. Kerry testifies along with Secretary of Energy Ernest Moniz at a Senate Foreign Relations Committee hearing last week to review the Iran nuclear agreement. (Andrew Harnik/AP)

Several of the questions directed at Kerry focused on the threat Iran poses to Israel, whose prime minister, Benjamin Netanyahu, has been a vocal critic of the agreement. Rep. Brendan Boyle (D-Pa.) said he had heard some of the concerns directly from the Israeli ambassador to the United States.

“I believe that Israel, the region and the world are far more secure if Iran does not move towards the possession of a nuclear weapon,” Kerry replied. “I believe the agreement is the best way to achieve that.”

Kerry noted that Rep. Sander M. Levin (D-Mich.), the longest-serving Jewish member of Congress, had just come out in support of the nuclear accord.

Both Kerry and Moniz denied that an agreement in which Iran will give international inspectors access to its nuclear facilities represents a “secret side deal” that is being hidden from Congress.

The head of the International Atomic Energy Agency, Yukiya Amano, went to Tehran in early July — a trip that was widely reported at the time — for discussions on finishing an investigation into suspicions that Iran conducted secret research into nuclear weapons more than a decade ago. Amano said that process could be completed by mid-December, fulfilling one of the agreement’s prerequisites for sanctions relief.

“There’s no secret deal,” said Kerry. “There is an agreement, which is the normal process of the IAEA, where they negotiate a confidential agreement, as they do with all countries, between them and the country. And that exists.”

Kerry said he has received briefings about the IAEA agreement but not actually seen it. He said Congress would be provided more details in confidential briefings.

He grew visibly agitated as the hearing wore on.

“Congressman, I don’t need any lessons from you about who I represent,” he said after Rep. Scott Perry (R-Pa.). complained that the United Nations Security Council had voted on the agreement before Congress had a chance. “I’ve represented and fought for our country since I was out of college.

“This is America’s interest, because America is the principal guarantor of security in the region and particularly with respect to some of our closest friends,” Kerry continued. “Now, we believe that Iran was marching towards a weapon or the capacity to have a weapon, and we’ve rolled that back, Congressman.”