The White House’s National Security Adviser Jake Sullivan made the announcement, saying it was a response to Houthi attacks on shipping in the Red Sea, Al Jazeera reports.

“Today, in response to these continuing threats and attacks, the United States announced the designation of Ansarallah, also known as the Houthis, as a Specially Designated Global Terrorist,” Sullivan said in a statement.

However, he added that the designation — which comes into effect in 30 days — could be reevaluated if the Houthis cease attacks in the Red Sea and the Gulf of Aden.