US fires missile into ship trying to breach blockade to reach Iran

The Gambia-flagged cargo ship Lian Star is no longer transiting to Iran. (Supplied: Marine Traffic/Kenro Oshita)

The US military has fired a missile into the engine room of a merchant vessel trying to break through its blockade of Iranian ports, the Central Command says.

The ship remains adrift in the Gulf of Oman and US forces have not boarded it, a US official with knowledge of the situation says, speaking on condition of anonymity.

US President Donald Trump has yet to decide on whether to move ahead with a tentative deal to extend the ceasefire with Iran and reopen the Strait of Hormuz.

The US military has stopped a merchant vessel trying to break through its blockade of Iranian ports by firing a missile into its engine room, the US Central Command says.

The Gambia-flagged cargo ship Lian Star ignored more than 20 warnings from US forces overnight as it tried to enter an Iranian port, the military said on Saturday, local time.

The ship remained adrift in the Gulf of Oman and US forces have not boarded it, a US official with knowledge of the situation said, speaking on condition of anonymity to discuss military operations.

With the latest action, US military has stopped six ships trying to breach the blockade. One was allowed to proceed. Another 116 ships have been redirected, the military said.

The US launched the blockade on April 17 in response to Iran effectively closing the strait after the war in the Middle East began with US and Israeli strikes on February 28.

The Strait of Hormuz is a strategic waterway between Iran and Oman that links the Persian Gulf to the Arabian Sea. (Getty: Gallo Images/Orbital Horizon/Copernicus Sentinel Data)

A fragile ceasefire has held since April 7. Now the region awaits word on whether a deal can be reached to extend it by 60 days, while talks would be held on Iran's disputed nuclear program.

Events in the Strait of Hormuz, a key waterway between Iran and Oman, have shaken the global economy.

Shipments of significant amounts of oil, natural gas and related supplies like fertiliser are largely stranded, increasing the strain on consumers and food producers.

The US blockade seeks to limit Iran's own shipments and further weaken its access to cash, creating more pain for its long-weakened economy.

The US president has been weighing a tentative agreement that would open the Strait of Hormuz and begin talks on Tehran's nuclear program.

US President Donald Trump met with advisers on Friday but has yet to decide on whether to move ahead with a deal to extend the ceasefire and reopen the strait. Iran has said