Tehran has reportedly told its neighbors in the Middle East not to support a potential US attack

Iran has placed its forces on high alert, warning neighboring countries that host American bases not to support potential US strikes, Reuters reported on Sunday, citing an official familiar with the matter.

The reported move follows a letter from US President Donald Trump to Iranian Supreme Leader Ayatollah Ali Khamenei urging direct talks aimed at halting Tehran's nuclear program. Trump has threatened a bombing campaign if a new deal is not reached.

Tehran, which denies seeking nuclear weapons, rejected the demand for direct talks. Foreign Minister Abbas Araghchi called the proposal "meaningless" and questioned its sincerity. "If you want negotiations, then what is the point of threatening?" he said.

According to Reuters, Tehran "has issued notices to Iraq, Kuwait, the United Arab Emirates, Qatar, Turkey and Bahrain," warning that allowing American forces to use their airspace or territory would be considered an act of hostility. "Such an act will have severe consequences for them," an unnamed official was quoted as saying.

The same source stated that Khamenei had ordered Iran's armed forces to be placed on high alert.

In 2015, Tehran signed an UN-backed agreement to limit its nuclear activity in exchange for sanctions relief. Trump unilaterally withdrew from the deal in 2017 and reimposed restrictions as part of his "maximum pressure" campaign against Iran. The Islamic Republic responded by scaling back its compliance under the 2015 accord.

Iran remains open to indirect talks via Oman, according to Reuters. "Indirect talks offer a chance to evaluate Washington's seriousness about a political solution," the Iranian official said. Talks could begin soon if US signals are "genuine," though the process may be "rocky," the official added.

Araghchi said on Sunday that Iran wanted talks on "equal footing." He described the US as "a party that constantly threatens to resort to force in violation of the UN Charter and that expresses contradictory positions from its various officials."

Major General Hossein Salami, chief commander of Iran's Islamic Revolutionary Guard Corps (IRGC), warned on Saturday that the country was "ready for any war."

Russia had earlier said that US threats to Iran were "unacceptable" and called for restraint.