A 15-point plan aimed at putting an end to the conflict was drafted by Washington and sent to Tehran, a person familiar with the matter told Reuters on Tuesday.
"Has the level of your inner struggle reached the stage of you negotiating with yourself?" Ebrahim Zolfaqari, spokesperson for the unified command of Iran's armed forces, Khatam al-Anbiya Central Headquarters, taunted the US leadership.
Zolfaqari said US investments and pre-war energy prices would not return as long as Washington does not accept that regional stability is guaranteed by Iranian armed forces.
Iran's leadership has previously said it cannot negotiate with the US as Washington has attacked the country twice during high-level negotiations in the past two years.
Iran had a "very bad experience with American diplomacy," Iran's foreign ministry spokesperson Esmaeil Baghaei told India Today on Tuesday. There was no dialogue or negotiations with Washington, as Iran's armed forces are focused on defending the country, he added.
Four weeks into the war that has killed thousands, created the worst energy shock in history and sparked global inflation fears, there was no letup in airstrikes from Iran and Israel on Wednesday.
The Israeli military said in a Telegram post it had launched a wave of strikes targeting infrastructure across Tehran. It later said its air force had struck two naval cruise missile production sites in Tehran.
The semi-official Iranian SNN News Agency said the strikes hit a residential area in the city, with rescuers searching the rubble.
Kuwait and Saudi Arabia said they had repelled fresh drone attacks, without saying where they came from. Drones targeted a fuel tank at Kuwait International Airport, causing a fire but no casualties, Kuwait's Civil Aviation Authority said.
Iran's Revolutionary Guards said it had launched a new wave of attacks against locations in Israel including Tel Aviv and Kiryat Shmona, as well as US bases in Kuwait, Jordan and Bahrain, Iranian state media reported.
Trump told reporters at the White House on Tuesday the US was in "negotiations" with "the right people" in Iran to end the war, adding the Iranians wanted to reach a deal very badly.