World Bulletin / News Desk
The group of roughly a dozen Green Berets arrived on the Saudi Arabian border with Yemen late last year, according to the New York Times, which reported the previously undisclosed mission.
The Trump administration had maintained that U.S. support for the Saudi-led operation is limited to targeting and intelligence assistance, as well as mid-air refueling and other logistical help.
Asked about the Times' report, the Pentagon said the U.S. is "there and we are helping them with securing their borders" but did not explicitly acknowledge the Army special forces deployment.
The Green Berets are assisting Saudi forces in locating and destroying Houthi rebels’ ballistic missile caches and launch sites, according to the Times.
But even the previously disclosed U.S. assistance has come under congressional scrutiny amid a mounting civilian death toll from the Saudi-led coalition's bombing campaign in Yemen, as well as what some lawmakers call an illegal deployment of U.S. military forces.
"Our troops continue to see their involvement increase in the Saudi-led war against the Houthis. This is an unconstitutional and unauthorized use of military force," Representative Ro Khanna said in a statement.
Senator Bernie Sanders, who previously sought the Democratic nomination in the 2016 White House race, voiced "strong concerns" about the U.S. role in Yemen, saying "the Trump administration is getting the U.S. more involved in a war in Yemen without congressional authorization".
"We must prevent the U.S. from getting dragged into another never-ending war," he said on Twitter.
Sanders along with Republican Senator Mike Lee and Democratic Senator Chris Murphy forced a vote on ending U.S. support for the Saudi campaign in March, but the effort ultimately failed.
In 2015, Saudi Arabia and its Sunni-Arab allies -- who accuse Yemen's Houthi rebels of serving as an Iranian proxy -- launched a massive military campaign aimed at rolling back Houthi gains.
Saudi Arabia accuses Iran of providing arms and ballistic missiles to the Houthis, who overran much of Yemen in 2014, including the capital, Sanaa. But its campaign has led to widespread condemnation from rights groups and the UN for its impact on civilians.