Two US Navy warships transited the Strait of Hormuz to begin clearing Iranian-laid mines, US Central Command said Saturday — a claim Tehran denied as the Revolutionary Guards threatened to deal “severely” with military vessels crossing the strategic waterway.’

The announcement of the first such transit since the US-Israeli war with Iran began came shortly after President Donald Trump said Washington had started “clearing out” the strait, through which a fifth of the world’s crude oil passes.

“Today, we began the process of establishing a new passage and we will share this safe pathway with the maritime industry soon to encourage the free flow of commerce,” said CENTCOM commander Admiral Brad Cooper.The USS Frank E. Peterson and the USS Michael Murphy are the guided-missile destroyers involved in the operation, but CENTCOM said that “additional US forces including underwater drones” could join the effort in coming days.

Iran “strongly rejected” Washington’s claims that US vessels entered the strait, military spokesperson Ebrahim Zolfaghari told state TV.

“The initiative for the passage of any vessel lies with the armed forces of the Islamic Republic of Iran,” he was quoted as saying.

Iranian state broadcaster IRIB later quoted the Revolutionary Guards’ Navy Command as saying: “Any attempt by military vessels to pass through the Strait of Hormuz will be dealt with severely.”

It added that passage of the strait would only be “granted to civilian vessels under specific conditions.”