Australia will spend more than $100 million per year until 2020 training soldiers and police in Afghanistan in a two-year extension of its non-combat role for Kabul-based soldiers, the Government announced on Friday.

Dramatic advances have seen the Taliban gain back as much ground as it lost after the Coalition invasion 15 years ago, according to United Nations estimates.

Pointing to a 2017 timetable for Australian defence chiefs to revise the role and number of Australian troops in Afghanistan, a spokesman for Defence Minister Marise Payne said "that is a decision for further down the track".

The announcement comes a day after US President Barack Obama's announcement of a slowdown in the US military withdrawal from Afghanistan.

"The security situation in Afghanistan remains precarious," Mr Obama said. "Afghan security forces are still not as strong as they need to be."

More than 8,000 US soldiers will stay in the country into next year. Under initial plans, US troop numbers were to be reduced to 5,500 by year's end.

The US and Australian extensions come as evidence points to the growing activity of insurgents within the country.

A small Islamic State group presence has been established, and the Afghan Government has conceded there is evidence the alliance between the Taliban and Al Qaeda has reformed.

"They (Al Qaeda) are really very active," Afghan Defense Minister Mohammed Masoom Stanekzai said. "They are working behind other networks."

US forces destroyed a 70-square kilometre facility in southern Kandahar province last year after it was discovered to be an Al Qaeda-run training facility supported by the Taliban.

The US have since acknowledged they underestimated the strength of Al Qaeda in the country.