Iran on Monday issued a warning to Israel not to cross its "red lines" in the Gulf after reports emerged that the country has deployed a submarine in the region.
Foreign ministry spokesman Saeed Khatibzadeh stressed the Islamic republic would defend itself against any American military "adventure" in the runup to the January 20 handover of power in Washington.
The statement came a week after the US Navy announced a nuclear submarine was being deployed to the Gulf, in a new show of force directed at Iran.
Earlier, Israeli media reported that the country's submarine has crossed the Suez Canal also headed for the Gulf, a report that has not been officially confirmed or denied.
Khatibzadeh told an online news conference, "Everyone knows what the Persian Gulf signifies for Iran. Countries very well how high the risk is raised if the red lines of Iran are crossed."
Iran has threatened to attack Israel since the assassination of its top nuclear scientist, Mohsen Fakhrizadeh, in late November, in a raid blamed on the Jewish state.
In a strikingly similar move to the reported Israeli submarine crossing of the Suez Canal, a US nuclear submarine crossed the Strait of Hormuz on Monday as the anniversary of the killing of Iranian General Qassem Soleimani by a US drone approached.
"We have sent messages to the US government and our friends in the region (warning) the current US regime not to embark on a new adventure in its final days at the White House," said Khatibzadeh.
He said Iran was not seeking to increase tension and called for "rational people in Washington" to take the same line until President-elect Joe Biden replaces Trump in the White House.
Decades-old tensions between Washington and Tehran have soared since 2018 when Trump unilaterally withdrew the United States from the Iran nuclear deal.
The arch enemies have twice come to the brink of war since June 2019, especially following the killing of Soleimani.