Australia will send an extra 150 troops to Afghanistan due to the deteriorating security situation, Prime Minister John Howard said today.
The addition will briefly boost Canberra's commitment to Afghanistan to more than 600.
"Security beyond Kabul, particularly in the east and south, is the worst since the Taliban fell - suicide bombings have increased," Mr Howard told parliament.
Australia was one of the first countries to commit forces in late 2001 to the US-led war which ousted the Taliban and began fighting al-Qaeda.
"We must stick with our allies and stand up for our values," said Defence Minister Brendan Nelson, outlining the new Australian Defence Force (ADF) deployment.
"A failure to do so will inevitably mean leaving the next generation hostage to global forces they will never control."
The bulk of the extra troops are being sent to protect Australian military engineers, who will join a Netherlands-led reconstruction team in the central province of Uruzgan.
"The level of violence has increased in Afghanistan in recent months as the Taliban and other terrorist groups, including al-Qaeda, seek to chip away at the credibility of the Afghan government and prevent reconstruction taking place," said Howard.
Almost 80 foreign soldiers, hundreds of militants and Afghan forces as well as civilians and aid workers have been killed in the worsening violence this year.
No Australian troops have been killed in enemy fighting in Afghanistan or Iraq, but Howard warned "the possibility of ADF casualties cannot be discounted".
In July, six Australian special forces troops were wounded in fighting in southern Afghanistan.
Australia's 200 special forces troops are due to return home next month, leaving about 400 soldiers in Afghanistan.