The federal government says it has been working to secure the release of an Australian man kidnapped in Afghanistan following his appearance in a video.
The Afghan Taliban has released a clip showing Timothy Weeks pleading with the US government to negotiate with his captors and saying that unless a prisoner exchange is agreed to, he would be killed.
Mr Weeks, an Australian teacher at the American University in Kabul, and his American colleague Kevin King were seized near the campus in August.
The video, which Mr Weeks said was made on New Year's Day, shows the two men, both bearded, asking their families to put pressure on the US government to help secure their release.
Addressing US President-elect Donald Trump, who is due to take office on January 20, Mr Weeks said the Taliban had asked for prisoners held at Bagram air field and at Pul-e-Charkhi prison on the outskirts of Kabul to be exchanged for them.
"They are being held there illegally and the Taliban has asked for them to be released in our exchange. If they are not exchanged for us, then we will be killed," he said.
"Donald Trump sir, please, I ask you, please, this is in your hands, I ask you please to negotiate with the Taliban. If you do not negotiate with them, we will be killed."
A spokesperson for the Department of Foreign Affairs and Trade in Canberra said Australia had been working closely with other governments to secure Mr Weeks' release.
"We have also been providing consular support to the man's family, who have requested privacy," they said in a statement.
"Out of respect for his family's wishes, and in the interests of his own safety and well-being, we will not be commenting further."