Last month, amid a rapid-fire escalation in tensions between Washington and Tehran, the Iranian Foreign Minister, Mohammad Javad Zarif, received an unexpected invitation—to meet President Donald Trump in the Oval Office. The diplomatic overture was made by Senator Rand Paul, the Kentucky Republican, during a meeting with Zarif in New York on July 15th, according to American and Iranian sources and a well-informed diplomat.

With President Trump’s blessing, Paul had been working on the idea for several weeks, in consultation with the White House and the State Department. An intermediary had reached out to the Iranians on Paul’s behalf three weeks before Zarif was due in New York for meetings at the United Nations. On July 14th, the day before leaving for New York, Paul had a discussion about Iran with the President, while playing a round at the Trump golf course in Sterling, Virginia.

On July 15th, Paul and his senior adviser, Doug Stafford, met Zarif at the elegant residence of Iran’s U.N. ambassador, on Fifth Avenue, a block from the Metropolitan Museum. In his decades as a diplomat, Zarif, who studied under Condoleezza Rice’s Ph.D. adviser, at the University of Denver, has built a modest rolodex with the private numbers of members of the House and Senate. “I always see people from Congress,” Zarif told me and a small group of journalists later that week, without naming names. But this was his first meeting with Paul, who is on the Senate Foreign Relations Committee.

The two men initially talked about long-standing issues, notably Tehran’s nuclear program, and also recent flare-ups in the Persian Gulf, according to the sources. In May and June, the United States accused Tehran of sabotaging six oil tankers just beyond the strategic Strait of Hormuz. On June 20th, Iran shot down one of America’s most sophisticated drones, claiming that it was flying over Iranian airspace. Trump considered military retaliation, but called it off at the last minute, because of projected casualties. While Zarif was in New York, the U.S. downed an Iranian drone, on July 18th. As tempers frayed, Washington was abuzz with worry about the prospect of a new war in the Middle East. Paul’s mission was to break through the messy layers of conflict and launch a direct diplomatic channel, at the highest level. The overture was a miniature version of Trump’s tactic in circumventing traditional diplomacy by dealing directly with the North Korean leadership.

During an hour-long conversation, Zarif offered Paul ideas about how to end the nuclear impasse and address Trump’s concerns. He later outlined some of them to our group of journalists and subsequently in more detail to me. “As a diplomat, I have to always think about alternatives,” he told us. Among them was the idea that the Iranian Parliament could codify, in law, a fatwa issued by Iran’s Supreme Leader, originally in 2003 and again in 2010, that forbids the production or use of nuclear weapons. “We consider the use of such weapons as haraam [forbidden] and believe that it is everyone’s duty to make efforts to secure humanity against this great disaster,” Ayatollah Ali Khamenei said, in 2010.

But, if Trump wanted more, he would also have to offer more, Zarif suggested. Another possibility was moving forward one of the later steps of the nuclear deal brokered between Iran and the world’s six major powers in 2015—the accord that Trump abandoned in May, 2018. Zarif said that Iran could bring forward ratification of the so-called Additional Protocol, which is currently due to be implemented by 2023—potentially this year. The protocol, which has already been signed and ratified by a hundred and forty-six nations, allows more intrusive international inspections—on both declared and undeclared nuclear sites in member states—in perpetuity. “The Additional Protocol is a crucial means by which the world verifies that Iran is not pursuing nuclear weapons,” Daryl Kimball, the executive director of the Arms Control Association, told me on Friday. “If you don’t trust the Iranians, you want inspections in perpetuity.” By ratifying the protocol, Iran would forfeit one of the so-called sunset clauses in the 2015 deal, which had triggered deep skepticism among Republicans, some Democrats, Israel, and Saudi Arabia. In exchange, Zarif suggested, Trump could go to Congress to lift sanctions on Iran, as originally provided under the 2015 nuclear deal but not ratified in legislation. Both sides would then feel more secure in the commitments sought in the original deal.

Paul proposed that the Iranian diplomat lay out the same ideas to Trump in person. The President, Paul said, had authorized him to extend an invitation to meet in the Oval Office as early as that week, the U.S., Iranian, and diplomatic sources told me. A White House spokesperson declined to comment about the invitation on the record.

Trump has long defied the hawkish members of his staff—particularly his national-security adviser, John Bolton—who have been skeptical about the potential for successful high-level diplomacy with Iran. On Wednesday, a senior Administration official told reporters, in a teleconference briefing, “President Trump has been very open that he is ready to speak to the senior leadership in Tehran and that he has certainly not prevented any of our friends or allies from communicating with them as well.” Trump relayed a message about potential diplomacy to Iran’s Supreme Leader through the Japanese Prime Minister, Shinzo Abe, in June. “The President has placed no restrictions on elected officials having conversations with foreign counterparts,” the official said.

During its first two years, the Trump Administration reached out to Iran about possible meetings at least eight times, including twice when Trump and the Iranian President, Hassan Rouhani, were both at the U.N. General Assembly, European and Iranian diplomats told me. One of those requests, relayed through the French President, Emmanuel Macron, in 2017, was made on the same day that Trump railed against Iran at the General Assembly. Trump called the Islamic Republic a corrupt dictatorship whose leaders had turned a wealthy country “into an economically depleted rogue state whose chief exports are violence, bloodshed, and chaos.” Insulted, Rouhani declined the invitation to meet privately.

Zarif told Paul that the decision to meet Trump in the Oval Office was not his to make; he would have to consult with Tehran. He expressed concern that any meeting might end up as little more than a photo op, without substance, the sources told me. Last December, when I interviewed Zarif at the Doha Forum, he said that Tehran wanted more than just a photograph and a two-page document from any future talks—a reference to the limited outcome of Trump’s first summit with the North Korean leader, Kim Jong Un, in Singapore last year. “We don’t just do a talk for a photo opportunity and a two-page document,” he said. “We have a hundred-and-fifty-page document,” a reference to the detailed nuclear accord that Trump abandoned.

After his meeting with Paul, Zarif relayed the overture to Iran’s leaders. They did not approve a meeting—at this time. Rouhani is due to attend the U.N. General Assembly next month.

Senator Lindsey Graham, the South Carolina Republican, is reportedly also working with the Administration on Iran, albeit on a different track. He was part of the group that played golf—and discussed Iran—with Trump on July 14th. Graham, who is more hawkish than Paul, has been consulting with allies on the framework of a wider deal, according to the Daily Beast. It would call on Tehran to accept the so-called 123 Agreement, which was outlined in legislation passed in 1954. It imposes nine safeguards on the use of nuclear material—to insure that it is not diverted to make a bomb—in exchange for U.S. coöperation on nuclear technology. The United States has 123 Agreements with forty-nine countries and Taiwan.