Rubio: Iran has mined large segments of Strait of Hormuz

Secretary of State Marco Rubio said Tuesday that Iran has mined "large segments" of the Strait of Hormuz, indicating that explosives in the strategic sea lane are more widespread than previoulsy acknowledged.

"They're firing on commercial ships and they've mined large segments of Hormuz — international waters," Rubio told the Senate Foreign Relations Committee, in his first appearance before Congress since the U.S. and Israel launched the war against Iran on Feb. 28.

Iran must agree in any deal with the U.S. that it will not charge a toll to transit Hormuz, will not fire on commercial ships and will help remove any mines it has laid in the strait, the Secretary of State said.

"What they're doing is unlawful and illegal," Rubio told the Senate.

Hormuz is a crucial chokepoint for the global energy market, with about 20% of global oil supplies passing through the sea lane before war. Oil tanker traffic through the strait has plunged due to threats from Iran, triggering the the largest supply disruption in history.

President Donald Trump cast doubt early in the war that Iran was deploying mines. In a Truth Social post on March 10, Trump warned Tehran that if it has deployed mines in Hormuz, they were to be removed immediately. The president said the following day that he didn't think Iran had mined the strait when asked by a reporter outside the White House.

Trump said on April 23 that he ordered the U.S. Navy to "shoot and kill" any boat that was deploying mines in the strait. He said U.S. mine sweepers were "clearing the Strait" at an accelerated tempo.

But Iran's mines still pose a major challenge to the resumption of large scale commercial traffic more than a month after Trump said the US. was clearing the explosives. The president demanded Friday that Iran "complete the immediate removal and/or detonation of any mines" that the U.S. has not already removed.

It is still unclear how many mines are in Hormuz and where they are located in the sea lane, said Jack Kennedy, head of Middle East country risk at S&P Global Market Intelligence. Traffic through Hormuz is unlikely to return to prewar levels until a solid demining effort has taken place, Kennedy said.

The White House did not respond to a question about how many mines are believed to remain in Hormuz. The Pentagon has destroyed numerous mines and over 40 minelaying vessels, a White House official told CNBC.

"The President has been clear that these are short-term, temporary disruptions," the official said.