The US military has warned ships in the Strait of Hormuz to 'prepare to be boarded' as it enforces Donald Trump's blockade.

US Central Command (CENTCOM) released audio of the ominous radio message on Wednesday, even as the President stated that he is 'permanently opening' the Strait.

'The US has announced a formal blockade of Iranian ports in coastal areas,' a military officer says.

'This is a legal action. All vessels are advised to immediately return to port if leaving, and discontinue transit to Iran if that is your next port of call, do not attempt to breach the blockade.' 

The officer warns that any vessels breaching the blockade 'will be boarded for interdiction and seizure' and that 'we will use force.'

The military's statement directly contradicts Trump's earlier claim on Truth Social that the strait is 'permanently open' after secret talks with Xi Jinping, claiming the Chinese leader had agreed to stop arming Iran.

'China is very happy that I am permanently opening the Strait of Hormuz,' Trump wrote on Truth Social. 'I am doing it for them, also - And the World. This situation will never happen again.'

A senior White House official told the Daily Mail that, despite Donald Trump’s promise to reopen it, 'the blockade is fully in effect and working.' It remains unclear whether Trump was declaring the strait open to shipping traffic immediately or signaling an intent to reach a permanent resolution as peace talks with Iran continue.

After peace talks with the Islamic regime collapsed over the weekend, the President launched a naval blockade of Hormuz, a critical oil chokepoint through which one-fifth of the world’s supply flows.

Trump imposed the blockade to push Tehran back to the negotiating table, with the President reportedly reluctant to resume the bombing campaign, which has brought chaos to the Middle East.

During the start of Operation Epic Fury, Iran retaliated by choking off traffic through the strait with swarms of explosive speedboats, drones and naval mines.

The regime has also sought to impose de facto tolls on passing oil tankers, allowing favored partners like China and India to transit more freely while pressuring Western vessels.

The blockade has sparked condemnation from China who is the number one importer of Iranian oil. 

Xi Jinping called Trump's decision 'dangerous and irresponsible' while demanding that the world must not 'revert to the law of the jungle.'

Since the blockade has gone into effect, ships operating in the Gulf have begun adopting tactics to avoid detection by the US military, according to the New York Times.  

'Now, we are starting to see vessels going dark or using "zombie" or random identification,' Ami Daniel, a maritime intelligence data analyst, told the paper.

The report notes that in the past 24 hours, ships linked to Iran have begun manipulating the global system used to surveil maritime traffic as they move in and out of Iranian ports. 

On Tuesday, the US military blocked six oil tankers from passing through the strait.

The Pentagon, meanwhile, is preparing to send 6,000 more troops to the region aboard the USS George HW Bush and several other warships.