US President Donald Trump threatened in an expletive-laden social media post Sunday to strike Iran's power plants and bridges if the Strait of Hormuz was not reopened the next day.

Following an 48-hour ultimatum he issued on Saturday, Trump said on his Truth Social platform that "Tuesday will be Power Plant Day, and Bridge Day, all wrapped up in one, in Iran. There will be nothing like it!!!"

"Open the Strait, you crazy bastards, or you'll be living in Hell - JUST WATCH!" wrote the president, adding: "Praise be to Allah."

Trump also said that the US has rescued a “seriously wounded, and really brave" F-15 crew member "from deep inside the mountains of Iran."

Trump said that the rescued officer was a “highly respected Colonel,” adding that such an operation “is seldom attempted because of the danger to ‘man and equipment.’”

“The second raid came after the first one, where we rescued the pilot in broad daylight, also unusual, spending seven hours over Iran. An AMAZING show of bravery and talent by all!” he said.

“I will be having a News Conference, with the Military, at the Oval Office, on Monday, at 1:00 P.M.,” he added.

Trump said earlier on Sunday that the US rescued a military officer in "one of the most daring Search and Rescue Operations in US history."

Noting that the officer suffered injuries, Trump said he "will be just fine."

He said the mission followed the separate rescue of another US pilot on Friday, which was not announced earlier to avoid jeopardising the second operation.

Regional tensions have escalated since the US and Israel launched a joint offensive on Iran on February 28, killing more than 1,340 people to date, including then-Supreme Leader Ali Khamenei.

Tehran has retaliated with drone and missile strikes targeting Israel, as well as Jordan, Iraq, and Gulf countries hosting US military assets. Iran has also restricted the movement of ships through the Strait of Hormuz.