Prime Minister Turnbull revealed NATO had asked him to consider sending more troops to Afghanistan during his Anzac Day visit earlier this year.
He met with US Defense Secretary James Mattis as well as NATO officials in Kabul.
“We have been asked to consider additional resources, and we are actively considering that. We're open to that,” Prime Minister Turnbull told reporters in Sydney.
“We've obviously got to look at the commitments of the Australian Defence Force in other parts of the region and, indeed, in other parts of the world.”
Australia currently has 270 troops training and mentoring Afghan security forces as part of Operation Highroad.
The ADF ended combat operations there in 2014 after first arriving in 2001 to stop it being used as a safe haven for terrorists and stabilise the country.
“I would argue that anyone who went into Afghanistan realistically in 2001 should have had an expectation of staying there for a long, long time,” retiring Defence Department Secretary Dennis Richardson told the National Press Club in Canberra.
“We have now moved beyond the involvement in the direct fighting phase. We are now placing emphasis on building the Afghan forces themselves and that will take a long, long time.”
The country would continue to rely heavily on foreign military and financial assistance, he added.
“We will need to continue to give financial assistance to Afghanistan for many years to come,” Mr Richardson said.
“Afghanistan has total income from within its own sources in country of less than $3 billion a year. It costs over $4 billion a year to keep the Afghan national security forces in operation.”
Forty-two Australian soldiers died in Afghanistan and nearly 250 were wounded in what became the ADF’s longest combat operation.