Australia's war in Afghanistan is over, with Australian Defence Force combat troops in the air on their way home.

Prime Minister Tony Abbott and Defence Minister David Johnston announced on Monday that the last Australian troops had left Oruzgan for good.

''This war is ending, not with victory, not with defeat but with hope that Afghanistan is a better place and that Oruzgan in particular is a better place for our presence,'' Mr Abbott said in Sydney.

Mr Abbott said that Australia left the province with better infrastructure, government and medical facilities. He also added that girls there now go to school. But the Prime Minister acknowledged that Australia had paid a high price for the 12 years of war in Afghanistan, which saw 40 ADF members killed and 261 seriously wounded.