"Not at all" concerned about potential clash with Iran: Trump

The US is "not at all" concerned about a potential clash with Iran, President Donald Trump said Friday, warning that Tehran will pay a price like nobody has ever paid if it does "anything foolish" in the region.

President Trump's warning came a day after he said a US naval ship destroyed an Iranian drone in the Strait of Horumz after it had come within its "threatening range", a development that is likely to escalate the simmering tensions between the two countries.

"No, not at all," Trump told reporters at the White House on friday when asked how concerned he was about a potential clash with Iran in the region.

"We have the greatest people in the world, we have the greatest equipment in the world. We have the greatest ships -the most deadly ships, we don't want to have to use them, but they're the most deadly ships ever conceived. And we hope for their sake they don't do anything foolish," he said.

"If they do, they will pay a price like nobody's ever paid," Trump warned.

The Strait of Hormuz is a strait between the Persian Gulf and the Gulf of Oman. It provides the only sea passage from the Persian Gulf to the open ocean and is one of the world's most strategically important choke points.

Pentagon chief spokesperson Jonathan Hoffman said on Thursday the Iranian drone was destroyed at approximately 10 am local time when the amphibious ship USS Boxer was in the international waters conducting a planned inbound transit of the strait.

Trump told reporters on Thursday that Boxer took defensive action against the Iranian drone, which had "closed into a very, very near distance", approximately 1,000 yards.

He said it ignored multiple calls to stand down and was threatening the safety of the ship and the crew.

"The drone was immediately destroyed. This is the latest of many provocative and hostile actions by Iran against vessels operating in international waters," he said.

The incident threatens to inflame already strained ties between Washington and Tehran, which worsened last month after Iran shot down a US surveillance drone it said was flying over its airspace.

Trump almost launched a military strike in response, but later said he called it back at the last minute when he decided the estimated death toll would have been too high.