U.S. Secretary of State Mike Pompeo on Monday called on Houthi rebels to cease attacks on Saudi Arabia after an airport in the country suffered from a drone attack.
Pompeo also singled out Iran, who the U.S. accuses of funding and supporting the Houthis, for putting the lives of Americans in Saudi Arabia at risk.
The attack on the Abha International Airport on Sunday, according to the secretary, caused one death and 20 injuries, and was the second strike on the Saudi airport in two weeks.
"These Iranian-backed attacks are unacceptable, and all the more reprehensible given that they targeted innocent civilians. They also put Americans living, working, and transiting through Saudi Arabia at risk," Pompeo said in a statement.
"We call on the Iran-backed Houthis to end these reckless and provocative attacks on behalf of the Iranian regime," he said.
Impoverished Yemen has been wracked by conflict since 2014, when the Houthis overran much of the country, including capital Sanaa.
The conflict escalated in 2015 when Saudi Arabia and its Sunni Arab allies launched a wide-ranging military campaign aimed at rolling back Houthi gains in Yemen and shoring up the country's Saudi-backed government.
An estimated 8.4 million people are at risk of severe famine and more than 22 million people, 75 percent of Yemen's population, are in need of humanitarian assistance.
Riyadh has repeatedly accused the Houthis of acting as a proxy force for Iran, Saudi Arabia's arch-rival in the region.
The secretary urged the Houthis to work within the bounds of the UN-led peace process "to end the conflict and adhere to the commitments they made in Sweden."
Pompeo is currently in Saudi Arabia on a trip to discuss tensions with Tehran, and said "the United States will continue to stand with all of our allies and partners in the region."
"We will continue to pursue peace and stability in Middle East," Pompeo said. "And we will continue our pressure campaign until Iran stops its torrent of violence and meets diplomacy with diplomacy."