The official, who spoke on condition of anonymity, added that Supreme Leader Ali Khamenei had placed Iran's armed forces on high alert.
Although US President Donald Trump has demanded direct negotiations, the official said Iran is open to a diplomatic path through intermediaries.
“Indirect talks offer a chance to evaluate Washington's seriousness about a political solution with Iran,” the official said. Talks via Oman could start soon if signals from the US align, though the official warned the path may be rocky.
Iran has issued formal warnings to Iraq, Kuwait, the UAE, Qatar, Bahrain and Turkey that allowing the US to use their airspace or territory during any attack would be treated as an act of hostility. Any such action “will have severe consequences for them,” the official said.
On Wednesday, Iranian state media reported that Kuwait had reassured Iran it would not permit aggression from its soil. Other governments approached by Reuters either declined to comment or did not respond. Turkey’s Foreign Ministry said it was unaware of any warning but suggested such messages could be delivered through alternative channels.
Meanwhile, Iran’s top military commander, Mohammad Bagheri, revealed the details of the Supreme Leader’s response to a letter sent by Trump on March 7.
“Negotiation directly is not acceptable, but indirect negotiation is not a problem,” Khamenei said in the message, according to Bagheri, the Chief of Staff of Iran's Armed Forces.
“You were the most disloyal and untrustworthy party in past negotiations, and thus there is no trust in you. However, we are not closing the door. If you act sincerely, negotiations can happen.”
According to Bagheri, Khamenei also told Trump that Iran is not pursuing a nuclear weapon. “We will respond with all our strength to any threats, but we are not warlike and will not start a war.”
Trump has warned Iran would be bombed if it did not agree to a new nuclear deal, prompting Khamenei to say on Monday that the Islamic Republic would deal a "strong blow" in retaliation for any attack.
Iran has also threatened to target American interests in the region, including its strategic Diego Garcia naval base in the Indian Ocean if it is attacked by the US.
The threats to neighbouring countries have escalated over recent months. In October, in the wake of Iran's attack on Israel which led to a retaliatory Israeli strike, The Wall Street Journal reported at the time that countries given warnings included Jordan, the United Arab Emirates, Saudi Arabia and Qatar, all of which host US forces.
It has since led to a complicating of regional dynamics. "US defense officials acknowledged that some regional partners have told the Pentagon that they don’t want Israeli warplanes flying over their territories or US troops launching offensive operations from inside or over their airspace," the WSJ reported.
"The Arab countries have said the US forces are allowed to conduct self-defense operations, the officials said," it added.
