Donald Trump has threatened to “blow up” Oman if it fails to “behave” in a casual aside during a cabinet meeting, as the US scrambles to reopen the strait of Hormuz.

The US president made the threat after reports of talks between Iran and Oman about jointly charging a toll for ships passing through the crucial waterway, which has been all but closed since the start of the US-Israel war on Iran.

“The strait is going to be open to everybody,” Trump declared on Tuesday. “Nobody’s going to control it. We’re going to watch over it. We’ll watch over it. But nobody’s going to control it. That’s part of the negotiation that we have.”

The strait – which typically carries about a fifth of the world’s oil supplies – has been blockaded by Iran since late February, triggering a global energy crisis and raising fears for the world economy.

Tehran wants to persuade Oman, a US ally, to support a mechanism to collect tolls from vessels transiting through the strait, the Associated Press has reported in recent days, citing a regional official.

“They would like to control it,” said Trump, who stressed the strait is part of international waters.

In an extraordinary threat, he added: “Oman will behave just like everybody else. Or else we’ll have to blow them up. They understand that. They’ll be fine.”

Trump’s efforts in recent weeks to strike a peace deal with Iran have so far failed to bear fruit. During Wednesday’s meeting, he accused Iran of trying to stall the agreement and “outwait me” until November’s midterm elections in the US.

When Trump signaled he was on the verge of a deal at the weekend, Republican hawks who had strongly backed his controversial decision to order war on Iran alongside Israel issued a rare rebuke.

Roger Wicker, who chairs the Senate armed services committee, said the “rumored 60-day ceasefire” would be a “disaster” in a post on social media. “Everything accomplished by Operation Epic Fury would be for naught,” he added.