WASHINGTON >> President Joe Biden said today that U.S. military strikes against Iranian-backed Houthi rebels in Yemen will continue, but he acknowledged that the American and British bombardment has yet to stop the militants’ attacks on vessels in the Red Sea that have bedeviled global shipping.

Two U.S. officials said the United States conducted a fifth strike this morning that targeted another missile launcher site, and two missile launchers were struck. The officials spoke on the condition of anonymity to provide details that were not yet public.

Biden said the U.S. would continue the strikes in an exchange with reporters before departing the White House for a domestic policy speech in North Carolina.

“When you say working, are they stopping the Houthis, no. Are they going to continue, yes,” Biden said.

The U.S. military fired another wave of ship- and submarine-launch missile strikes against Houthi-controlled sites on Wednesday, marking the fourth time in days it has directly targeted the group in Yemen as violence that ignited in the wake of the Israel-Hamas war continues to spill over in the Middle East.

The strikes were launched from the Red Sea and hit 14 missiles that the command deemed an “imminent threat.”

The strikes followed an announcement Wednesday that the U.S. has put the Houthis back on its list of specially designated global terrorists. The sanctions that come with the formal designation are meant to sever violent extremist groups from their sources of financing, while also allowing vital humanitarian aid to continue flowing to impoverished Yemenis.

Despite sanctions and military strikes, including a large-scale operation carried out by U.S. and British warships and warplanes that hit more than 60 targets across Yemen, the Houthis keep harassing commercial and military ships. The U.S. has strongly warned Iran to cease providing weapons to the Houthis.

For months, the Houthis have claimed attacks on ships in the Red Sea that they say are either linked to Israel or heading to Israeli ports. They say their attacks aim to end the Israeli air-and-ground offensive in the Gaza Strip that was triggered by the Palestinian militant group Hamas’ Oct. 7 attack in southern Israel.

However, the links to the ships targeted in the rebel assaults have grown more tenuous as the attacks continue.

The attacks have targeted commercial shipping vessels transiting through the critical Bab el-Mandeb Strait that links markets in Asia and Europe since the Oct. 7 attack by Hamas and Israel’s subsequent war against the militant group in Gaza.

Separately, the U.S. and its allies have formed Operation Prosperity Guardian to protect ship traffic, and currently warships from the United States, France and the United Kingdom are patrolling the area.

“These strikes will continue for as long as they need to continue,” National Security Council spokesman John Kirby said today, adding, “I’m not going to telegraph punches one way or another.”