The top US military officer is vowing long-term commitment to Afghanistan, touting progress in the war against the Taliban and its Al-Qaeda allies ahead of an American drawdown.

Admiral Mike Mullen, the chairman of the Joint Chiefs of Staff, said on the "Charlie Rose" television interview show Tuesday that although some troops would be withdrawn, a continued US presence was assured.

"Since I've been out there in the last three and a half, four years, it's still the leading question is, 'You left us before, are you going to leave us again?'" he said.