US and Iran trade fire in Strait of Hormuz

The US military says it has shot down four drones Iran launched toward the Strait of Hormuz and struck some of Tehran's coastal surveillance radar sites in response.

"The attack drones posed an immediate threat to regional maritime traffic," US Central Command said on social media.

The US military is enforcing a blockade on Iranian ports in response to Tehran's chokehold on the crucial corridor for global oil and natural gas shipments, which has sent energy prices spiking.

US Central Command said it hit the radar sites, including an island in the strait, "to defend against further attacks".

Hours later, US CENTCOM said its forces had intercepted seven Iranian ballistic missiles fired towards Kuwait and Bahrain that posed an immediate threat to regional maritime traffic.

US forces then struck Iranian coastal surveillance radar sites in Goruk and Qeshm Island, a statement said.

CENTCOM said initial assessments indicated six of the missiles launched by Iran were intercepted and a seventh did not reach its intended target.

Iran's Islamic Revolutionary Guard Corps (IRGC) confirmed its forces had fired on four tankers that attempted to cross the Strait of Hormuz without its permission.

The IRGC also said it would hold the US responsible for any consequences relating to the complete closure of the strait for oil and gas exports if American forces continued "mischief".

The strikes are the latest in a series of back-and-forth attacks that have strained the tenuous ceasefire in the war and efforts to reach a deal to extend that truce.

Earlier this week, Iranian drones heavily damaged a passenger terminal at Kuwait's main airport, killing one person, wounding dozens and briefly closing the airfield.

Despite the attacks raising new concerns that the ceasefire could collapse, US President Donald Trump told reporters "the situation with Iran seems to be going quite well".

"We're going to come out of Iran very quickly and it's going to be very strong one way or the other, whether it's a piece of paper or the very tough way," Mr Trump said at an event with farmers in the US state of Wisconsin.

"The very tough way is maybe the easier way, but we're going to come out, and your fertiliser prices are going to go way down, just like they were four months ago."

Mr Trump increasingly appears to be ensnared in a conflict that has settled into a holding pattern. US and Iranian negotiators reached a tentative agreement a week ago to extend the ceasefire by 60 days and start a new round of talks on Iran's nuclear program.

But Mr Trump has called for unspecified changes and Iranian officials have shown no public signs of closing on the deal.

Asked on Friday, local time, why it was taking so long, Mr Trump told NBC's Meet the Press it was because "it's a very hard thing for them", citing Iranians' "great independence" and the fact that "they're strong, they're proud".

"There are things they never thought they'd be doing that they're going to have to do," he said in the interview.

"They've got no choice, and it takes a little while."

Mr Trump said Iran still had 21-22 per cent of its missiles.

Meanwhile, his administration has lauded the ceasefire Lebanon and Israel have agreed to after US-brokered talks in Washington.

That is despite the Iranian-backed Hezbollah militant group rejecting the agreement and both sides launching new attacks.

The fighting in Lebanon, where Israeli forces have seized large swaths of the south, also threatens efforts to end the Iran war and reopen the Strait of Hormuz.

Iran has demanded that any lasting truce be extended to Lebanon.

AP