The White House said on Friday that it would take months to vet and train Syrian rebels to make them ready for battle against the Islamic State fighters, Xinhua reported.
National Security Adviser Susan Rice told reporters that the administration will move as fast as it "reasonably can" after Congress approved the president's plan to train and arm vetted Syrian rebels.
"But this is something that will take many months," she said at a White House daily news briefing.
President Barack Obama said the training program will be implemented outside of Syria in partnership with regional countries. Rice said the training facilities need to be constructed and the trainees need to be vetted and brought in for training.
"It is not something that one should expect will yield rapid and immediate fruit," Rice said, adding, "This is a serious training program, and we're serious about vetting those that we will be training and equipping."
Obama has pledged not to send U.S. troops into combat against the Islamic State, but rely on partner forces on the ground to support air raids carried out by U.S. warplanes.
The administration is reportedly aiming for training about 5, 000 what it calls "moderate" Syrian rebels in support of upcoming U.S. airstrikes inside of the Arab country.
Obama had authorized strikes on the Islamic State in Syria, but Rice refused to say when the president would give the go-ahead.