CANBERRA (REUTERS) - Australia will withdraw most troops from Afghanistan's south at the end of this year and shut down a major base for North Atlantic Treaty Organisation (Nato)-led forces, handing security to Afghan soldiers and police, Defence Minister Stephen Smith said on Tuesday.

Western and Afghan commanders, Smith said, had agreed that the major multinational coalition base at Tarin Kowt and its Nato airbase in Uruzgan province would close at the end of 2013.

Most foreign combat troops are due to leave Afghanistan by the end of 2014 under a planned security transition from foreign forces to Afghans.

"It is a necessary and logical and natural consequence of transition being effective," Mr Smith said.

"The effect of that closure will be that Australia will no longer have a permanent presence in Uruzgan province, and the majority of Australian defence force personnel will return."

Australia has around 1,650 troops in Afghanistan, including special forces, based mainly in volatile Uruzgan, and was an original member of the United States (US)-led coalition that helped oust the former Taleban government in late 2001.

It has lost 39 troops in the war, with 242 wounded.

The United States and Nato allies are racing against the clock to train a 350,000-strong force of Afghan soldiers to meet the 2014 deadline, although there is widespread scepticism that target can be met.

"A lot of people are worried about the military side and how are we going to get to 2014," Washington-based Australian counter-insurgency expert David Kilcullen told Australian Broadcasting Corporation (ABC) television.

"How are we going to hand over to the Afghans effectively and prevent the Taleban coming back?" he said on the ABC's Four Corners programme late on Monday.

Australia had not yet decided whether special forces troops would remain in Afghanistan next year or after 2014, Mr Smith said, with negotiations still underway with the Afghan government.