The United States launched additional strikes early on Thursday targeting two Houthi anti-ship missiles that were being prepared to fire into the Red Sea and deemed "an imminent threat" to shipping and U.S. Navy vessels in the region, the U.S. military said.

"U.S. Central Command forces conducted strikes on two Houthi anti-ship missiles that were aimed into the Southern Red Sea and were prepared to launch," U.S. Central Command said in a statement.

White House national security spokesman John Kirby, during a briefing aboard Air Force One, said the latest strikes were similar to those Wednesday taking aim at Houthi missiles that were prepared to fire in the southern Red Sea.

Biden separately told reporters earlier on Thursday that air strikes would continue even if they may not be halting the Houthi attacks.

"Are they stopping the Houthis? No. Are they gonna continue? Yes," Biden said before boarding Air Force One to leave the White House.

The latest U.S. strikes come one day after the U.S. returned the Yemen-based Houthi rebels to a list of terrorist groups.