CANBERRA - The main Australian base in Oruzgan Province in Afghanistan has officially closed, with the last Australian troops leaving Uruzgan province, Defense Minister David Johnston and Prime Minister Tony Abbott confirmed in a joint press conference on Monday.

Tony Abbott has announced the completion of the drawdown after Australia's longest ever overseas combat deployment.

David Johnston confirmed that the last troops left Oruzgan on Sunday. They left the base at Tarin Kot and are currently en route back home to Australia.

In addition, Abbott also said he believed Afghan forces were up to the job of maintaining security.

"The Afghan National Army has performed with considerable distinction over the last fighting season. Certainly our soldiers are very happy with the progress of the Afghan brigade they have been mentoring over the last few years," he said.

The 12-year mission saw 40 Australians killed and more than 250 seriously wounded. "We know that they've paid a high price, 40 dead, 261 seriously wounded," Abbott said.

The conflict, which began in 2001 as a mission to hunt down al Qaida, instead became a protracted fight against Taliban insurgents.

According to local media, more than 25,000 Australians have served in Afghanistan in a contribution that has also cost Australia more than 7.5 billion AU dollars ($6.72 billion).

According to the arrangements of the Australian government, around 400 military personnel will remain in Afghanistan in training and support roles, mostly in capital Kabul and in Kandahar.

The Australian government will also provide 100 million ($89.6 million) a year to help fund Afghanistan's defense forces.