More than 500 Afghan nationals who helped Australia's mission in Afghanistan have been resettled in Australia under a "discreet" relocation program, the Government says.

Defence Minister David Johnston said the employees and their families, including interpreters, were assessed to be at risk of harm after providing critical support to the Australian Defence Force and Australian Government agencies in Afghanistan.

"Many of these employees were placed at significant risk of harm by insurgents in Afghanistan, due to the highly visible and dangerous nature of their employment," Mr Johnston said in a statement.

The majority of those already settled in Australia arrived over the latter part of 2013 and early 2014.

The statement said the Government had wanted to conduct the process "with a high level of discretion, given the sensitivities and risks involved for the applicants and their families".

It is understood the Afghan employees and their families were keen to settle in Australia and said they were eager to start new lives and establish themselves as soon as possible.

The families were provided with accommodation, health services and household assistance.

"Many have already commenced employment or vocational training opportunities and their children are enrolled in school," Social Services Minister Kevin Andrews said in the joint statement.

Following the completion of Australia's mission in Uruzgan and the departure of Australian Defence Force personnel from the province, Australia will continue to provide training and advisory support to the Afghan National Security Forces.