President Donald Trump has threatened to bomb Oman – a US ally – if it “gets in the way” of his administration’s own talks with Iran, Fox News reports.

The US and Oman have been negotiating separately with Tehran to reopen the Strait of Hormuz, a waterway that is vital to the global economy. It has been largely closed for nearly six months during the US-Iran war.

A reporter for Fox said the US president made the threat to Oman while using an expletive during a phone interview.

Earlier in the day, Iranian officials said they were close to finalising a deal with Oman. Meanwhile, the future of talks between the US and Iran is unclear as a 60-day Memorandum of Understanding (MoU) between the two sides is expiring.

Speaking to reporters in the Oval Office on Monday, Trump was asked by BBC News if he was seeking an extension to the MoU, to which he replied: “No.”

Since the US and Israel attacked Iran in February, Tehran has largely blocked the Strait of Hormuz – through which about a fifth of the world’s oil and liquefied natural gas usually passes. Reopening it has been a key point of discussion.

Oman borders the southern side of the Strait and says it is a neutral country in this conflict. However it has suffered a number of strikes from Iran and is now playing a key role in negotiating with Tehran to reopen the waterway.

Washington has pursued its own efforts to secure the reopening. Fox reporter Trey Yingst quoted Trump as saying: “If Oman gets in the way, we’ll bomb the shit out of them.”

It is not clear what Trump thinks would constitute getting in the way of his ambitions for a deal.

During the same interview with Fox, Trump also said the US had a direct backchannel with the Islamic Revolutionary Guard Corps (IRGC), which is a major military, economic and political force in Iran.

An IRGC spokesman denied Trump’s claim.

A spokesman told semi-official Iranian news agency Tasnim News: “There are no talks taking place between IRGC officials and the Americans, and this lie by Trump is merely fantasies caused by the delusions and nightmares he has suffered as a result of defeat and desperation in the war.”

Trump made his threat to Oman a few hours after Iran had said the two countries had reached an agreement for ships to travel through the Strait.

Iran’s foreign ministry spokesman Esmaeil Baghaei told reporters “an understanding has been reached regarding the map of the transit route”.

He added that both sides would finalise the details before issuing a joint statement. Oman has previously described these talks as positive.

Earlier this month, Iranian Foreign Minister Abbas Araghchi said a full reopening was dependent on Iran receiving compensation from the US for what Tehran described as violations of the MoU.

Reuters – citing an Iranian official – previously reported that Tehran was seeking fees of between 5% and 7% of the price of cargoes from vessels who travel through the Strait.

While Trump said in his call with Fox that he had a direct backchannel with the IRGC, he said he was in no hurry to bring the war to a close.

“They’re good poker players, but they’re dying,” he was quoted as saying. “I have no time schedule. I’m not in a hurry.”

The Memorandum of Understanding between the US and Iran, signed on 18 June, was designed to bring about a ceasefire and at least partly reopen the Strait of Hormuz. But it fell apart a short time later when both sides resumed strikes.

On 8 July, Trump said the ceasefire was “over” and blasted Iran’s leadership as “scum” and “cuckoo” after fresh exchanges of fire.

As the MoU neared its formal expiry on Monday, Trump posted on his Truth Social network: “The number one goal is, and always will be, that Iran cannot have, in any way, shape, or form, a nuclear weapon.”