The United States on Monday expressed alarm at "genuine security threats" to Saudi Arabia from Yemen's Iran-aligned Houthis and elsewhere in the region after attacks on the heart of the Saudi oil industry, and it would look at improving support for Saudi defences, Reuters reported.
Earlier in the day, the US Embassy in Riyadh said Washington was committed to defending Saudi following Sunday's volley of drones and missiles, including one aimed at a Saudi facility vital to oil exports.
"We continue to be alarmed by the frequency of Houthi attacks on Saudi Arabia. Escalating attacks like these are not the actions of a group that is serious about peace," White House press secretary Jen Psaki said.
"We understand that they face genuine security threats from Yemen and others in the region…We will look for ways to improve support for Saudi Arabia's ability to defend its territory against threats," Psaki told a Washington news briefing.
Saudi-led coalition authorities said most of Sunday's drones and missiles were intercepted en route to their targets and there were no casualties or property losses from the attacks.
They targeted an oil storage yard at Ras Tanura, site of a refinery and the world's biggest offshore oil-loading facility, and a residential compound in Dhahran used by state-controlled oil giant Saudi Aramco.
The attacks, which drove Brent crude prices above $70 a barrel to their highest since January 2020, come at a time of friction in the decades-old alliance between Saudi Arabia and the United States as President Joe Biden puts pressure on Riyadh over its human rights record and the ruinous Yemen war.
"The United States stands by Saudi Arabia and its people. Our commitment to defend the kingdom and its security is firm," the US Embassy said in an Arabic-language Twitter post.
The Houthis have been battling a Saudi-led coalition in Yemen for six years in a conflict largely regarded as a proxy war between Saudi Arabia and Iran.
In new incidents on Monday, the coalition said it had intercepted and destroyed a ballistic missile and an explosive drone fired towards parts of the kingdom's southern region.
The Houthi military claimed to have hit a military target at Saudi Arabia's Abha airport, near the Yemen border, with a new type of ballistic missile.