U.S. Senator John McCain says the ongoing Taliban offensive in Afghanistan demands a reassessment of the Obama administration's current plan to drawdown U.S. forces.

McCain told reporters on Saturday that the Afghan national forces are fighting bravely, but suffering heavy losses in the field.

American and international troops have already stopped playing a combat role, remaining as trainers for local forces. The international numbers will be reduced further at the end of 2016. But McCain says any reduction should be based on conditions on the ground, not an arbitrary calendar date.

Meanwhile Afghan lawmakers rejected President Ashraf Ghani's nominee for defense minister, a position that has remained empty for more than nine month now. Masoom Stanekzai received just 84 out of the needed 107 votes for parliamentary approval.