US President Donald Trump on Wednesday re-designated Yemen's Houthi militias as a "foreign terrorist organization,” the White House said.
The move will impose harsher economic penalties than the Biden administration had applied to the Iran-backed group in response to its attacks on commercial shipping in the Red Sea and against US warships defending the critical maritime chokepoint.
"The Houthis' activities threaten the security of American civilians and personnel in the Middle East, the safety of our closest regional partners, and the stability of global maritime trade," the White House said in a statement.
The Houthis have carried out more than 100 attacks on ships plying the Red Sea since November 2023, saying they were acting in solidarity with Palestinians over Israel's war against Hamas in Gaza. They have sunk two vessels, seized another and killed at least four seafarers.
The attacks have disrupted global shipping, forcing firms to re-route to longer and more expensive journeys around southern Africa for more than a year.
The group has targeted the southern Red Sea and the Gulf of Aden, which are joined by the narrow Bab al-Mandab strait, a chokepoint between the Horn of Africa and the Middle East.