Washington is seeking to reduce the Iran-backed Huthis' military capabilities, but the Yemeni rebels have continued their attacks on shipping in the Red Sea, despite more than a week of strikes, and have vowed to keep targeting merchant vessels.

At around 4 am Sanaa time (0100 GMT), US "forces conducted airstrikes against a Huthi anti-ship missile that was aimed into the Gulf of Aden and was prepared to launch," a statement from US Central Command said Saturday.

"US forces determined the missile presented a threat to merchant vessels and US Navy ships in the region, and subsequently struck and destroyed the missile in self-defense."

"This action will make international waters safer and more secure for US Navy and merchant vessels," the statement said.

The Huthis began striking Red Sea shipping in November, saying they were hitting Israeli-linked vessels in support of Palestinians in Gaza. They subsequently declared American and British interests to be legitimate targets as well.

Saturday's operation marks the fifth round of strikes by the United States on the rebel group in recent weeks. Dozens of sites in Yemen have been hit, including a Huthi radar site and missiles Washington says posed a threat to civilian and military vessels.

Washington is also seeking to put diplomatic and financial pressure on the Huthis, re-designating them as a "terrorist" entity after dropping that label soon after President Joe Biden took office.

Yemen is just one part of a growing crisis in the Middle East amid the war in Gaza, where Israel's relentless bombardment and ground offensive have killed nearly 25,000 people, mostly women and children, according to Gaza's health ministry.

Israel's campaign began after the unprecedented October attacks by Hamas resulted in the deaths of about 1,140 people in Israel, mostly civilians, according to an AFP tally based on official Israeli figures.