Saudi Arabia and its coalition partners transferred US-made weapons to al Qaeda-linked fighters, hardline Salafi militias, and other factions waging war in Yemen, in violation of their agreements with the United States, CNN reported.
The weapons have also made their way into the hands of Iranian-backed rebels battling the coalition for control of the country, exposing some of America's sensitive military technology to Tehran.
Saudi Arabia and the United Arab Emirates, its main partner in the war, have used the US-manufactured weapons as a form of currency to buy the loyalties of militias or tribes, bolster chosen armed actors, and influence the complex political landscape, according to local commanders on the ground and analysts who spoke to CNN.
By giving the military equipment to third parties, the Saudi-led coalition is breaking the terms of its arms sales with the US. A US Department of Defense official told CNN that an investigation has been launched into the issue.
Previous CNN investigations established that US-made weapons were used in a series of deadly Saudi coalition attacks that killed dozens of civilians, many of them children.
In the aftermath of the killing of journalist Jamal Khashoggi in the Saudi embassy in Istanbul, the U.S.'s role in the Saudi-led war in Yemen has been under increased scrutiny.
Many lawmakers believe that Saudi Crown Prince Mohammed bin Salman ordered the murder.
The Senate voted 56-41 in December to pass a resolution that would withdraw U.S. forces in or “affecting” Yemen, except troops fighting al Qaeda and associated forces.
However, the then-Republican controlled House blocked Yemen war powers resolutions from coming to the floor for a vote.
In the new Congress, it is expected that lawmakers will once again push Trump to change the administration's policy toward Saudi Arabia.
Rep. Ro Khanna (D-Calif.) told The Hill on Wednesday that he expects the resolution on the House floor in the next month.
"This will be the first time in the history of this country since 1973 that we will successfully pass a war powers resolution through the Senate and through the House," Khanna said.
Trump is unlikely to sign the war powers measure into law.
However, the Trump administration ended its mid-air refuelling support of Saudi-led coalition aircraft in November. (ANI)