Iran’s Islamic Revolutionary Guards Corps (IRGC) said on Sunday that any military vessels attempting to approach the Strait of Hormuz would be considered a violation of the two-week ceasefire with the US, and warned that it would be dealt with harshly and decisively.

“The strait is under the control and smart management of Iran’s Navy,” the Guards said in a statement reported by Iranian state media, adding it is “open for the safe passage of non-military vessels in accordance with specific regulations”.

The IRGC has also warned that enemies would be trapped in its “deadly vortex” in case of any miscalculation.

“All traffic … is under the full control of the armed forces,” the Guards naval command said in a Persian language post on X.

“The enemy will become trapped in a deadly vortex in the strait if it makes the wrong move,” it added, posting a video showing vessels in crosshairs.

The IRGC’s warning came after US President Donald Trump, in a surprise announcement, said the United States Navy would begin the process of blockading vessels entering or leaving the Strait of Hormuz, citing concerns over maritime security and alleging that Iran had threatened shipping in the waterway.

After Trump’s announcement, Iran’s Parliament Speaker Mohammad Bagher Ghalibaf said that his country would not give in to threats.

“If they fight, we will fight, and if they come forward with logic, we will deal with logic. We will not bow to any threats, let them test our will once again so that we can teach them a bigger lesson,” Iranian media reported.

Hormuz, a key shipping lane off the coast of Iran, has been virtually blocked by Tehran since the United States and Israel started bombing Iran on February 28, though reopening the strait was ostensibly a condition of the ceasefire put in place earlier this week.

Around a fifth of global crude oil and liquefied natural gas (LNG) had been passing through the waterway in peacetime, and its blockage has resulted in a global fuel crisis.

Trump said in his Truth Social post that US forces had been instructed to interdict vessels in international waters that had paid what he described as “illegal tolls” to Iran.

He further warned of military consequences if Iranian forces targeted US or commercial vessels, saying Washington remained prepared to escalate its response.

“Any Iranian who fires at us, or at peaceful vessels, will be BLOWN TO HELL! Iran knows, better than anyone, how to END this situation which has already devastated their Country.”

He also indicated that other countries could join the proposed blockade, while reiterating that Iran would not be allowed to benefit from what he called “extortion” in international waters.

Trump reiterates threat

The US president’s post came the same day when talks between Washington and Tehran ended without any agreement.

But, he says that the Iranians “haven’t left the bargaining table”.

“I predict they [will] come back, and they give us everything we want — and I told my people, I want everything. I don’t want 90 per cent, I don’t want 95pc. I told them, I want everything. They have no cards,” he during a phone interview on the Fox News show ‘Sunday Morning Futures with Maria Bartiromo’.

He also reiterated his threat to destroy Iran’s power plants and other civilian energy infrastructure if no deal was reached to end the conflict in the Middle East, which began with the US and Israel launching strikes on Iran on February 28.

“I could take out Iran in one day,” Trump said. “I could have their entire energy, everything, every one of their plants, their electric generating plants, which is a big deal.”

Earlier, in his Truth Social post, he said that talks with Iran in Islamabad had yielded progress on “most points” but failed to secure agreement on Tehran’s nuclear programme.

Delegations from the two sides, with Ghalibaf leading the Iranian side and US Vice President JD Vance leading Washington’s effort, had met in Islamabad on Saturday for talks mediated by Pakistan.

The trilateral talks, which commenced on Saturday afternoon, saw the US and Iranian delegations engage in discussions over three sessions, with teams of experts from the two parties exchanging written texts after each session.

After discussions that went on for at least 20 hours, Vance held a press conference in the federal capital on Sunday morning, announcing that “unfortunately, we were unable to make any headway”.

Iran’s Parliament Speaker Mohammad Bagher Ghalibaf, in his first comments after the conclusion of the dialogue between the two sides, said it was now time for the United States to decide whether it could “earn” Tehran’s trust.

Iran’s Foreign Ministry Spokesperson Esmaeil Baqaei, in remarks carried by Iranian state media, said the delegations reached “understanding” on several issues. However, he stated that “on 2-3 important issues, views were far apart, and ultimately, the talks did not lead to an agreement”.

In a lengthy statement on Turth Social, Trump said the nearly 20-hour meeting had gone “well” overall, but stressed that the “only point that really mattered” — Iran’s nuclear ambitions — remained unresolved.

Trump further said he had been fully debriefed by Vice President JD Vance, Special Envoy Steve Witkoff and Jared Kushner on the meeting held in Islamabad, which he said took place under the leadership of Pakistan’s Field Marshal Asim Munir and Prime Minister Shehbaz Sharif.

He described the Pakistani leadership as “extraordinary”, adding that they had thanked him for what he claimed was his role in preventing a potential war with India that could have cost millions of lives.

“I have been fully debriefed by Vice President JD Vance, Special Envoy Steve Witkoff, and Jared Kushner, on the meeting that took place in Islamabad through the kind and very competent leadership of Field Marshal Asim Munir, and Prime Minister Shehbaz Sharif, of Pakistan. They are very extraordinary men, and continuously thank me for saving 30 to 50 million lives in what would have been a horrendous War with India. I always appreciate hearing that — The amount of Humanity spoken of is incomprehensible,” said the US president.

“In many ways, the points that were agreed to are better than us continuing our Military Operations to conclusion, but all of those points don’t matter compared to allowing Nuclear Power to be in the hands of such volatile, difficult, unpredictable people,” said Trump in the Truth Social post.

Trump said his representatives became “very friendly and respectful” towards their Iranian counterparts during the prolonged talks, despite deep differences between the two sides.

He said the Iranian officials, Mohammad-Bagher Ghalibaf, Abbas Araghchi and Ali Bagheri, remained “unyielding” on what he described as the most important issue — Tehran’s nuclear programme.

He reiterated that Iran would “never have a nuclear weapon”.

Additional input from AFP