US President Donald Trump on Monday again warned Iran of severe consequences, saying Washington would respond forcefully if American ships were targeted, while noting Tehran appeared more flexible in talks.

In an interview with Fox News, Trump said that if Iran attacks any American vessel operating under “Project Freedom,” the United States would retaliate decisively.

“We have more modern weapons and equipment than before and are fully capable of dealing with any potential threat,” Trump said.

He added that Iran was showing increased flexibility in negotiations but did not provide further details.

Trump described ongoing US actions in the Strait of Hormuz as a “grand military strategy,” calling it one of the most significant operations in recent times.

Tensions between Iran and the United States have risen in recent days over the Strait of Hormuz, with both sides issuing strong statements.

Trump also said that South Korea should join US efforts to protect shipping near Iran, adding that Defence Secretary Pete Hegseth would hold a news conference on Tuesday with Joint Chiefs Chairman Dan Caine.

Earlier, there was a fire and ​an explosion on a vessel operated by ‌South Korean shipper HMM in the Strait of Hormuz on Monday, the foreign ministry in Seoul said.

The government was ​checking intelligence that the vessel, HMM Namu, ​may have been attacked, Yonhap News reported ⁠, citing government officials.

There were no casualties reported, and ​authorities were investigating what caused the blaze that, ​HMM said, broke out in the engine room of the Panama-flagged cargo ship.

Twenty-four crew members, including six Korean nationals, ​were on board, the company told Reuters.

The ​US military said two US Navy guided-missile destroyers had entered ‌the ⁠Gulf to break an Iranian blockade and that two US merchant ships had transited the Strait of Hormuz, after Iran said it had prevented a ​US warship ​from entering the ⁠Gulf.

“Our government will communicate closely with relevant countries regarding this matter and ​take necessary measures to ensure the safety ​of ⁠our vessels and crew members inside the Strait of Hormuz,” South Korea’s foreign ministry said in ⁠a ​statement.

Seoul has said 26 South ​Korean-flagged vessels were stranded there.