The prime minister is sceptical about the assurances on safe travel given by the Taliban government, which has declared "full independence" after the United States completed its military exit.

"I'm cautious about how substantial they will be and for how long they will be in place. Afghanistan is a place where the situation is deteriorating," he told reporters in Canberra.

Working to get more people out is a key issue for Australia's Five Eyes partners - the US, UK, Canada and New Zealand - and other coalition partners.

"We'll work together to continue to provide as many people the opportunity for a new life in Australia," he said.

Foreign Affairs Minister Marise Payne said the undertaking by the Taliban is being closely watched by the international community.

"It is an expectation in terms of the ability for safe travel and safe transit that we are very focused on," she said.

"We know that for those who remain in Afghanistan, it's a question of very significant concern."

People who are still in Afghanistan who have been granted temporary safe haven visas will be contacted by Home Affairs about what to do when it is safe.

"The processing of those visas continues to be a priority," Senator Payne said.

A humanitarian disaster is unfolding in the war-torn nation, despite 122,000 people being evacuated including more than 4000 in Australia's airlift.

Hassan Noor, Asia regional director for Save the Children, said children and their families still in Afghanistan were also facing a drought, COVID-19 and a harsh winter.

"The military has left, but we urgently call on the international community to stay and support the children of Afghanistan," he said.

"With food, clean water, shelter, with education - if this doesn't happen, the efforts of the last 20 years will truly have been in vain."

Australian Associated Press