WASHINGTON — The Bush administration offered a far more generous package than the current nuke deal in its efforts to thwart Iran’s nuclear program, Secretary of State John Kerry told the Council on Foreign Relations on Friday, but Tehran rejected it.

The 2008 offer involved the US improving overall relations with Iran, “supporting Iran in playing an important and constructive role in international affairs,” and providing Iran with agricultural and technological aid, Kerry said.

He referred to a document dated June 12, 2008 that detailed proposed US concessions to Iran in exchange for Iran’s suspension of all nuclear enrichment and reprocessing. Kerry said that the list of US proposed commitments appeared “under a cover note signed by the P5+1 foreign ministers including then-secretary of state Condoleeza Rice.

The list, said Kerry, included commitments to: “recognition of Iran’s right to nuclear energy for peaceful purposes; treat Iran’s program in the same manner as that of any non-nuclear weapons state party to the party after international confidence in the exclusively peaceful nature of Iran’s program was restored; provide technical and financial assistance for peaceful nuclear energy including state of the art power reactors; support for research and development and legally binding fuel supply guarantees; improve relations with Iran and support Iran in playing an important and constructive role in international affairs; work with Iran and others in the region on confidence building measures and regional security; a reaffirmation of the obligation to refrain from the threat or use of force; steps toward normalization of trade and economic relations; support for energy partnership, support for agricultural development, civil projects, support for civilian aviation, and assistance in Iran’s economic and social development.”

US president George W. Bush shake hands with Benjamin Netanyahu, head of the opposition, at the Knesset on May 15, 2008. Bush delivered a speech to mark the Jewish state's 60th birthday. (Photo credit: Lior Mizrahi/pool/FLASH90)

US president George W. Bush shake hands with Benjamin Netanyahu, head of the opposition, at the Knesset on May 15, 2008. Bush delivered a speech to mark the Jewish state’s 60th birthday. (Lior Mizrahi/pool/FLASH90)

“All of that was offered in exchange for the suspension of Iran’s nuclear process and then negotiations,” Kerry said. But Iran, Kerry said “said no, and that was the end of the dialogue.” That deal, Kerry said, was a non-starter.

“Iran refused, and they went from about 300 centrifuges to 19,000,” giving Iran the ability to manufacture 10-12 bombs, Kerry told the New York audience.

He said that despite everything that was offered at the time, Iran continued with its program because it “truly believed” it had a right to enrich uranium, and because Iran resented that the US had supported Iraqi president Saddam Hussein against them and that the international community had never issued a resolution condemning the gassing of Iranians during the Iran-Iraq war in the early 1980s.

“They felt that they needed to have their own independent program because nobody would come to their assistance,” Kerry argued.

The secretary of state used the story to emphasize that “sanctions weren’t going to stop [the Iranians]. You’re not going to sanction them into submission.”

The secretary of state, who is countering allegations made by Republican lawmakers that the Obama administration wanted the deal more than the Iranians, also cited three occasions during the 18-month-long negotiations on the deal signed last week on which he said he was prepared to walk away from the talks due to Iranian intransigence.

Kerry said that he was prepared to walk out of a series of talks in Lausanne, and went to Iranian Foreign Minister Mohammad Javad Zarif’s hotel room to tell him that he would do so; he didn’t detail what the topic of contention was.

He offered more details about a second instance in London, in which he said that Iran was “trying to walk back on the number of centrifuges.” According to Kerry, he called and said he “wasn’t coming the next day.”

The third instance was during the wind-up to the final deal in Vienna, where Kerry publicly stated his displeasure with what was apparently a dragging-out of talks at the end of the process.

Kerry has been front and center in the Obama administration’s campaign to sell the Iranian deal to skeptics. He has spent recent days trying to promote the deal to doubtful Americans as the Republican-majority, 535-member Congress has 60 days to review the agreement.

Earlier Friday, he appeared on NBC’s “Today” show and will later Friday meet with the leaders of the American Jewish Committee and the Conference of Presidents of Major American Jewish Organizations.

Kerry said Friday it would be embarrassing to him and a blow to US credibility on the world stage if Congress rejects the Iran nuclear deal. He also warned that a congressional rejection would not work to Israel’s favor.

Congress can pass a motion of disapproval, which Obama can veto. An override of the veto requires two-thirds approval in both the House and Senate.

“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,” Kerry warned at the Council of Foreign Relations event.

“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.”

AP and AFP contributed to this report.