The Iran-backed Houthis in Yemen have been designated as a foreign terrorist organization, Secretary of State Marco Rubio announced Tuesday, fulfilling one of President Donald Trump’s first promises upon taking office.

Rubio said the U.S. “will not tolerate” any country that does business with “terrorist organizations like the Houthis.”

“Today’s action taken by the State Department demonstrates the Trump Administration’s commitment to protecting our national security interests, the safety of the American people, and the security of the United States,” Rubio said in the statement. “Terrorist designations play a critical role in our fight against terrorism and are an effective way to curtail support for terrorist activities.”

The Houthis have carried out more than 100 attacks on vessels in the Red Sea following the Oct. 7, 2023, attacks by Hamas on Israel and the ensuing war in Gaza. The U.S. military has defended its warships patrolling the Red Sea and Bab al-Mandab Strait, escorting and preventing attacks on commercial ships by the Houthis.

After Trump suggested removing Palestinian from Gaza last month, the Houthis’ leader, Abdul Malik al-Houthi, said in a televised speech that the group would take military action against the U.S. and Israel.

There has been a policy debate at the highest levels of the U.S. military about what is the best way to counter the Houthis.

Some suggest a more traditional counterterrorism approach to the Houthis, with persistent strikes targeting the individuals planning and carrying out the ongoing attacks, while others want a more defensive approach that goes after Houthi infrastructure and weapons-storage facilities.

Fox News’ Jennifer Griffin contributed to this report.