American President Donald Trump announced on Sunday that the United States Navy will immediately begin blockading the Strait of Hormuz following Iran’s refusal to forgo its nuclear ambitions after peace talks.

In posts on Truth Social, Mr Trump said the blockade would begin shortly. 

He said that although the meeting between the U.S. and Iran in Islamabad, Pakistan, “went well,” with agreement on most issues, the nuclear programme remained unresolved.

“Effective immediately, the United States Navy, the finest in the world, will begin the process of blockading any and all ships trying to enter, or leave, the Strait of Hormuz,” Mr Trump declared.

He added that an agreement on free passage could be reached “at some point,” but accused Iran of preventing it “by merely saying, ‘There may be a mine out there somewhere that nobody knows about but them.”

Mr Trump described this as extortion and maintained that the U.S. and other world leaders would not be pressured.

The president said he had also directed the U.S. Navy to intercept vessels that paid toll to Iran, as they would not be granted safe passage.

“We will also begin destroying the mines the Iranians laid in the Straits,” Mr Trump said. “Any Iranian who fires at us, or at peaceful vessels, will be blown to hell.”

According to the president, other countries will be involved in the blockade to stop Iran’s “illegal act of extortion.”

He accused Iran of failing to open the Strait of Hormuz as promised, causing pain to countries worldwide: “As they promised, they better begin the process of getting this international waterway open and fast!”

The president said that while some agreements during the talks were better than continuing military operations in Iran, they were less important than stopping Iran’s nuclear programme.

Mr Trump disclosed that Vice President JD Vance, Special Envoy Steve Witkoff, and Jared Kushner had briefed him on the meeting in Islamabad.

Following Mr Trump’s announcement, Iran maintained that the Strait of Hormuz remains under the control and “smart management” of Iran’s Islamic Revolutionary Guard Corps (IRGC) Navy.

It said the passage was open to non-military vessels but warned That, “military vessels approaching the Strait of Hormuz will be considered a ceasefire breach and will be dealt with strongly.”

U.S. and Iranian officials held 21-hour peace talks days after Mr Trump announced a ceasefire.

Mr Vance earlier told a news conference that both countries had made no headway at the meeting, during which Iran’s Parliament speaker, Mohammad Bagher Ghalibaf, represented Tehran.

Iran blocked the Strait of Hormuz, a narrow channel through which 20 per cent of the world’s oil and gas is shipped, on February 28 after the U.S. and Israeli forces launched attacks on the Islamic Republic.