Only four or five U.S-trained Syrian fighters remain on the battlefield against ISIS militants, the top U.S. commander in the Middle East acknowledged Wednesday in the face of withering criticism from senators who dismissed the training program as a "total failure" and demanded a change of strategy.

Until now, the U.S. has declined to say how many of that group of trained Syrian rebels remained in the fight.

Austin urged patience, saying that over time the trained Syrian fighters will be able to join other rebel groups fighting along the Syrian border.

One of the problems has been that many Syrian fighters want training and equipment to fight the government forces of President Bashar Assad, but the U.S. program is limited to rebels who agree to only battle ISIS.

...