WASHINGTON — The Army's chief of staff says he believes more troops are needed in Afghanistan. But Gen. George Casey isn't saying exactly how many more should be sent into the war.

Casey says more troops would help cut into the Taliban's successes while U.S. forces continue training Afghan security forces.

President Barack Obama is considering several options to increase the number of troops fighting in Afghanistan, including Gen. Stanley McChrystal's preference of about 40,000 additional U.S. forces next year.

Casey appeared Sunday on NBC's "Meet the Press."