SYDNEY - Australia on Friday appointed a former commando soldier as the nation's new spy chief.

Duncan Lewis will become the new director-general of the Australian Security Intelligence Organisation (ASIO), taking over from David Irvine who retires after five years in the top job.

Lewis, 61, served in the Vietnam War as an infantry soldier, and later served with the United Nations Truce Supervision Organisation as a military observer during the 1982 Lebanon War.

He served in the Special Air Service (SAS) regiment and later commanded the unit before serving as army attache in Jakarta.

In 2000 he was promoted to brigadier and had a command role in the East Timor peacekeeping mission. In January 2001 he was appointed commander of Australian Special Forces, served in Afghanistan, and retired from the army in 2005, taking up the job of deputy secretary in the Department of Prime Minister and Cabinet, with responsibility for advising on national security, defence, intelligence and international relations.

In late 2008 Lewis was appointed national security adviser, and later defence department secretary.

Lewis later served as ambassador to Belgium, the European Union, Luxembourg and NATO.