Four senators introduced legislation on Thursday, June 21 that would bar President Barack Obama from providing military aid to Syria's rebels, saying the administration has provided too little information about what they see as a risky intervention, Reuters said.

The bill would prevent the Department of Defense and U.S. intelligence agencies from using any funds to support military, paramilitary or covert operations in Syria, directly or indirectly.

The bill's sponsors - Democrats Tom Udall of New Mexico and Chris Murphy of Connecticut and Republicans Mike Lee of Utah and Rand Paul of Kentucky - expressed doubts about Washington's ability to ensure weapons will not fall into the wrong hands, and called for debate in Congress before the United States becomes more involved in Syria's civil war.

"The president's unilateral decision to arm Syrian rebels is incredibly disturbing, considering what little we know about whom we are arming," Paul said in a statement.

Other lawmakers argued it was in the U.S. national security interest to get more involved in Syria. .