They discussed issues including "the escalating attacks by Iran-aligned militia groups on US troops in the Middle East" and "the illegal Huthi attacks on international shipping in the Red Sea," as well as humanitarian assistance for Gaza and support for Ukraine, Pentagon spokesman Major General Pat Ryder said in a statement.

"Secretary Austin thanked Secretary Shapps for the United Kingdom's steadfast support and leadership in coalition efforts to stave off further Huthi aggression, while defending naval and international commercial vessels exercising navigational rights and freedoms," Ryder said, referring to attacks on shipping by the Iran-backed Yemeni rebels.

US and British forces have launched joint strikes aimed at reducing the Huthis' ability to target vessels transiting the key Red Sea trade route -- attacks the rebels say are in support of Palestinians in the Gaza Strip, where Israel is at war with Hamas.

US and allied forces in Iraq, Syria and Jordan have been attacked more than 165 times since mid-October, many of them claimed by a loose alliance of Iran-linked armed groups that opposes American support for Israel in the Gaza conflict and the presence of Washington's troops in the region.

On Sunday, a drone struck a military base in northeastern Jordan, killing three US soldiers and wounding more than 40 -- the first American military deaths in an attack in the Middle East since the start of the Israel-Hamas war in early October.

Washington blamed Iran-backed militants for the attack, vowing a decisive response.