The senior official, who asked not to be identified, said two intermediary countries had conveyed proposals to Iran's foreign ministry for "reducing tensions or ceasefire with the United States".
The official did not give further details of the proposals or the intermediaries.
Ayatollah Mojtaba Khamenei, who had held his first foreign policy session since being named supreme leader, had responded that it was not "the right time for peace until the United States and Israel are brought to their knees, accept defeat and pay compensation," the official said.
He did not clarify whether Khamenei, who has not yet been pictured since being named last week to replace his slain father, had attended the meeting in person or remotely.
The US-Israeli war on Iran is now in its third week, with at least 2000 people killed and no end in sight.
The Strait of Hormuz remains largely closed off and allies have rebuffed US President Donald Trump's calls for them to help to reopen the vital waterway, through which about 20 per cent of global oil and liquefied natural gas flows.
Israel's Defence Minister Israel Katz said Israeli forces had killed Iran's security chief Ali Larijani, as well as Gholamreza Soleimani who led the volunteer Basij militia which plays a major role in domestic security.
Prime Minister Benjamin Netanyahu said Israel was weakening Iran's leadership to give its people the opportunity to rise up and topple the government.
"It won't happen in one go, it won't happen easily. But if we persist - we will provide them with the opportunity to take their destiny into their own hands," he added.
There was no immediate response from Iran to Israeli claims on Larijani's death
Iranian state media published a handwritten note by Larijani commemorating Iranian sailors killed in a US attack whose funeral was expected on Tuesday.
Larijani, secretary of the Supreme National Security Council, would be the most senior figure assassinated since Supreme Leader Ayatollah Khamenei was killed on the first day of Israeli-US airstrikes on February 28.
Since Khamenei's death, Larijani had become one of the most powerful figures in the Islamic Republic.
He held a series of senior jobs and was close to the slain leader but had a reputation for pragmatic relations with the system's often-rival factions.
There was no let-up in attacks by both sides early on Tuesday.
In Israel, where Iranian missile attacks have killed 12 people, air raid sirens sounded throughout the day in the commercial hub Tel Aviv and surrounding cities as loud blasts of interceptions were heard as far away as Jerusalem.
The Israeli military said it was targeting "Iranian regime infrastructure" with a new wave of strikes across Tehran, as well as Hezbollah sites in Beirut.
Foreign Minister Gideon Saar said Israel "had, in effect already won the war," but gave no timeline for when the war might end in a press conference in Jerusalem.
The head of the United States' National Counterterrorism Center, Joseph Kent, resigned on Tuesday, saying in a letter to Trump that he "cannot in good conscience" back the US war in Iran.
Iran "posed no imminent threat to our nation, and it is clear that we started this war due to pressure from Israel and its powerful American lobby," Kent said in a social media post.
with AP
