Key lawmakers have moved to slash funding of a secret CIA operation to train and arm terrorists in Syria, a move that US officials said reflects rising skepticism of the effectiveness of the agency program.

Key lawmakers have moved to slash funding of a secret CIA operation to train and arm terrorists in Syria, a move that US officials said reflects rising skepticism of the effectiveness of the agency program and the Obama administration’s strategy in the Middle East, The Washington Post reported Saturday.

The House Intelligence Committee made a unanimous decision to cut as much as 20 percent of the funds flowing into a CIA program that officials said has become one of the agency's largest covert operations overseas, with a budget approaching $1 billion a year.

"There is a great deal of concern on a very bipartisan basis with our strategy in Syria,” said Rep. Adam B. Schiff (Calif.), the ranking Democrat on the House intelligence panel.

The cuts to the CIA program are included in a preliminary intelligence spending bill that is expected to be voted on in the House next week.

According to the US daily, "the measure has provoked concern among CIA and White House officials, who warned that pulling money out of the CIA effort could weaken U.S.-backed insurgents just as they have begun to emerge as effective fighters."

This week, President Obama expanded the US military’s role against the so-called 'Islamic State of Iraq and the Levant' (ISIL), unveiling plans to deploy American advisers to new bases in Iraq, while announcing no change to the limited American-led bombing campaign that began in Iraq and Syria last year. A separate Defense Department program authorized to train moderate fighters to combat ISIL has not yet begun.

"The cost of that CIA program has not previously been disclosed, and the figure provides the clearest indication to date of the extent to which the agency’s attention and resources have shifted to Syria," The Washington Post concluded.