Australia has extended its military mission in Afghanistan by six months to mid-2017 and potentially longer as the troubled nation battles a resurgent Taliban.

Australia also pledged on Friday to continue its $100 million a year commitment to the Afghan National Army and National Police until 2020.

President Barack Obama said Wednesday the United States would scale back plans to draw down troop numbers, with 8,400 to remain in Afghanistan next year.

Australia ended combat operations in Afghanistan at the end of 2013. But 270 troops remain on a training and assistance mission, which was due to conclude at the end of 2016. They will now stay at least until mid-2017.

The international contribution to Afghanistan is under discussion at a NATO summit this weekend in Poland.