Vance sent a letter last week to Rezaei, secretary of Iran's Supreme National Security Council and a former commander of the Islamic Revolutionary Guard Corps (IRGC), outlining the interests of both countries in possible negotiations, the newspaper reported on Thursday, citing a US official familiar with the discussions.
The letter stressed that Washington's main objective was to prevent Iran from obtaining a nuclear weapon, while recognizing Tehran's interests in rebuilding its economy and preserving its national sovereignty.
The vice president also told Iran it needed to appoint representatives authorized to negotiate over its nuclear program, according to the report.
Istanbul or Doha could host a meeting between Vance and Rezaei if the two sides agree to direct talks, the official said.
The Washington Post reported that US officials regarded Rezaei as an important contact because of his influence within Iran's security establishment and his access to Supreme Leader Mojtaba Khamenei.
Qatar returns to Tehran for new talks
Qatari mediators returned to Tehran on Friday to advance efforts toward an agreement between Iran and the United States, Reuters reported, citing an official briefed on the negotiations.
The mediators have been coordinating their efforts with Washington as they seek to narrow differences over the nuclear program and the economic restrictions imposed on Iran.
The two sides remain divided over the order of steps needed to reach an agreement. Washington wants nuclear issues addressed from the outset, while Tehran insists that the US first end its naval blockade and lift restrictions on Iranian oil exports.
Qatar presented Iran with a draft peace plan on Sunday, but a senior Iranian official subsequently described the ideas as unacceptable and said Tehran would not change its position on the nuclear issue.
Iranian Foreign Minister Abbas Araghchi said on Wednesday that Tehran was consulting closely with intermediaries on ideas for implementing its own seven-day proposal to end the war.
The Washington Post reported that Qatari representatives have maintained regular contact with Rezaei and other senior Iranian officials.
According to the newspaper, Iranian leaders regarded Vance's direct letter as a sign of respect, although there was no indication they had changed their nuclear position.
Washington sees Rezaei as central to negotiations
The Trump administration believes Rezaei could help secure support within Iran's leadership for a nuclear agreement, the Washington Post reported, citing the US official.
US intelligence officials believe Rezaei has maintained regular contact with Supreme Leader Mojtaba Khamenei, including discussions in recent days after receiving Vance's letter.
Rezaei, a former commander of the IRGC, has gained influence within Iran's political and security establishment and maintains connections with officials overseeing the economy, according to the report.
The newspaper said US officials viewed him as someone capable of securing agreement among Iranian leaders on sensitive nuclear issues.
Vance previously led US negotiations with Iran, including an April meeting in Islamabad with Iranian Parliament Speaker Mohammad Bagher Ghalibaf.
Those discussions involved possible sanctions relief and economic cooperation in exchange for a nuclear agreement, but they failed to produce a lasting settlement.
The Washington Post reported that US officials believe the opportunity to reach an agreement without further military action could be narrowing.
Trump says contact focused on medical supplies
US President Donald Trump confirmed Wednesday that he had approved Vance's outreach to Iran but said the contact concerned medical supplies rather than instructions to restart peace negotiations.
"They need help with medical supplies and various things. He asked me what I thought. I said, 'if you want to do that, that's OK,'" Trump told reporters.
"Basically, it's getting supplies in to help people that are not well," he added.
The Wall Street Journal first reported the letter to Rezaei, saying the contact was intended to explore whether Washington and Tehran could agree on a framework for negotiations.
Axios separately reported that Vance stressed the need for any renewed negotiations to address Iran's nuclear program.
The discussions come as Trump considers possible renewed strikes against Iran after the November 3 US midterm elections, according to reports by US media outlets.
Vance says Trump will not allow prolonged Iran war
Speaking at a Fox News town hall in Fort Worth, Texas, on Thursday, Vance said Trump would not allow the conflict with Iran to become a prolonged US military engagement.
"We've been involved in Iran in some form for seven months. The United States has been dealing with Iran for 47 years, and I promise you that Donald Trump is not going to let Iran become a forever war," Vance said.
He said opposing lengthy military interventions did not mean ruling out the use of force.
"I think there's a difference between criticizing foreign military misadventures and saying that you can never ever use the American military," he said.
"He's going to accomplish America's objectives, and then we're going to focus on the other things that we're doing," Vance added.
His comments came as US military officials prepared options for possible further strikes against Iran, with Trump yet to announce a decision.