Iran on Thursday condemned as “baseless” a move by US President Donald Trump to re-designate Yemen’s Tehran-aligned Houthi militia as a Foreign Terrorist Organization (FTO).

Iranian foreign ministry spokesperson Esmaeil Baghaei said that the move, which will impose harsher economic penalties than the Biden administration had applied to the Houthis, was “an excuse to apply anti-human sanctions against the Yemeni people.”

“Such arbitrary and baseless unilateral actions will further weaken the rule of law in international relations and threaten regional peace and stability,” Baghaei was quoted by state media as saying.

The Houthis, who control most of Yemen, 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.

In 2021, Joe Biden had dropped Trump’s terrorist designations to address humanitarian concerns inside Yemen. Biden last year designated the group as a “Specially Designated Global Terrorist” organization, but held off on applying the harsher FTO designation.