A U.S. Department of Defense official confirmed to CNN that the U.S. is investigating whether or not Saudi Arabia and its coalition members gave al-Qaida, Salafi militias and other factions in Yemen U.S. produced weapons.

CNN reported on Monday that U.S. weapons and highly sensitive military secrets sent to the Saudis and Emiratis ended up in the hands of U.S. rivals in Yemen, in violation of U.S.-Saudi coalition arms agreements.

The Trump administration's support for the Saudi-led coaltion in Yemen has long been controversial in the U.S. with the Senate voting 56-41 in December to pass a resolution that would withdraw most U.S. forces from Yemen.

Local commanders told CNN during its investigation that the Saudis and the United Arab Emirates are using U.S. weapons as currency to buy off different factions and militias in the Yemeni conflict - including Iranian-backed fighters.

CNN concluded that the transactions are “exposing some of America's sensitive military technology to Tehran and potentially endangering the lives of U.S. troops in other conflict zones.”

The conflict, widely seen in the region as a proxy war between Saudi Arabia and Iran, has been bogged down in a military stalemate for years.

A Sunni Muslim Arab coalition led by Saudi Arabia and the United Arab Emirates intervened in Yemen in 2015 to restore the government of Abd-Rabbu Mansour Hadi after it was ousted from power in the capital Sanaa by the Houthis in late 2014.

The Houthis control most urban centers in the poorest Arabian Peninsula nation while Hadi's government controls the southern port of Aden and a string of coastal towns.

Reuters contributed to this report