Mr Weeks, speaking in Sydney on Sunday, said his life as he had known "ceased to exist" when he and American Colleague Kevin King were abducted in 2016 outside the American University of Afghanistan in Kabul.

The pair worked as teachers at the time when four heavily armed Taliban suicide soldiers abducted them.

Mr Weeks also described how his three years in captivity had taken a toll on him and his family.

"The time I spent as hostage with the Taliban has had a profound and unimaginable effect on me," the 50-year-old said.

"I struggled to find words to express just how completely this has changed me.

"At times I felt as if my death was imminent and that I would never return to see those that I loved again.

"But by the will of God, I am here, I am alive, I am safe and I am free."

Mr Weeks told reporters that the ordeal had also "taken a great toll" on his father's health.

"After almost 1200 days, our ordeal ended as abruptly as it had begun," he said.

Last month, the Taliban released the pair as part of a hostage swap deal. In exchange for their release, three ranking Taliban prisoners have been released by Kabul and flown to Qatar.

Prior to his arrival back home, Mr Weeks and Mr King were handed over to US forces in southern Afghanistan and flown out of the country for medical care.

Mr Weeks also described how he and Mr King were kept in tiny, windowless cells in remote locations and often without proper medical care.

"At times, we spent long periods in the dark - that was quite difficult," he said.

Mr Weeks thanked his family, supporters, political leaders and various government agencies that "worked on the long and complex process that led to our final release".

"From the moment I sighted both black hawk helicopters and was placed in the hands of special forces, I knew my long and tortuous ordeal had come to an end," he said.

Mr Weeks said he now feels "a lot stronger" and that he always had hope.

"I never ever gave up hope and I think in that sort of situation, if you give up hope, there is very little left for you," he said.

He also said he believed the US Navy SEALs tried to rescue him and Mr King on six occasions. "A number of times, they missed us only by hours," Mr Weeks said.

One attempt in April had Mr Weeks fearing for his life as his captors brought him into an underground tunnel in the early hours of the morning, telling him Daesh (IS) had arrived, when it was the Navy Seals "right outside our door".

Machine gun fire raged above and he at one point lost consciousness, having been pushed backwards and rolled into the tunnel.

Mr Weeks said he felt "great joy" at the recommencement of peace talks between the US and Afghanistan governments and the Taliban.

He said he hoped to return to academic study in the future but will take a well-deserved holiday first.

The experience has left him feeling "stronger", with a belief that he can get through anything.

"It's given me a great sense of hope and a great sense of confidence," he said.

Joining him at the press conference were his sisters, Alyssa and Jo Carter.

Alyssa said the emotional family reunion was "incredible" while Jo described what her brother had been through as "totally unimaginable".