Sen. Mike LeeMichael (Mike) Shumway LeeSenate panel advances Trump's CIA nominee Doug Jones to oppose Haspel as CIA chief This week: Trump heads to Capitol Hill MORE (R-Utah) said Wednesday that if President Obama increases military aid to Syrian rebels, it could be like “pouring gas on a fire.”

Lee’s comments came after reports that Obama would announce that the United States would increase military support and training for moderate Syrian rebels who have been vetted.

“The situation in Syria is desperate, and we should be constantly assessing it for threats to U.S. security, but I am concerned that sending American weapons and training into this crisis could be like pouring gas on a fire,” Lee said.

Syrian rebels have been fighting the regime of President Bashar Assad. 

Some lawmakers, like Sen. John McCain (R-Ariz.), have been pushing the administration to do more to support the rebels who are struggling to fight against Assad’s chemical attacks. But others, like Lee, have cautioned that military aid to the Islamic rebels could backfire and be a repeat of Afghanistan, where the U.S. trained al Qaeda forces who later attacked the United States.

“When senior members of the president’s national security team cannot guarantee that assistance won’t fall into the hands of our enemies, or that the people we train today won’t be fighting alongside al Qaeda tomorrow, we should be very careful in considering approaches that could assist extremists in that conflict,” Lee said.

Last week, the Senate Armed Services Committee passed the National Defense Authorization Act (NDAA), which included a provision that would authorize the Department of Defense to train and equip Syrian forces.

The NDAA was reported out of committee on a 25-1 vote. Lee was the only senator on the committee to oppose the legislation.