Agreement that would free American and Australian professors kidnapped in Afghanistan in exchange for three Taliban figures reportedly has been reached between the Taliban and the Afghan government.

The prisoner swap involves American Kevin C. King, 63, and Australian Timothy Weekes, 50, professors at the University of Afghanistan, who were abducted at gunpoint as they left the university in Kabul in 2016, and Taliban figures Anas Haqqani, the younger brother of the Taliban’s military operations leader and leader of the Haqqani network; Hafiz Rashid, a senior Taliban commander, and Haji Mali Kahn, a senior commander and an uncle to the Taliban’s deputy leader. The Haqqani network is considered one of the deadlier factions of the Taliban.

Afghan President Ashraf Ghani announced the “tough but important decision” Tuesday, calling it a major step in reopening peace talks between the United States and insurgents. The Taliban have refused to negotiate with the Kabul government, which has demanded a monthlong ceasefire before any talks can be mounted.

The New York Times reported the health of King and Weekes has deteriorated since their abduction. Ghani said the Taliban figures would not be released until proof of life is obtained for the two professors.

In 2017, the Taliban released a video of the two captives in which they appeared pale and gaunt. A subsequent video showed them looking healthier but set a deadline of June 16, 2017, for their release. They appealed to President Trump for help.

"In order to pave the way for a face-to-face negotiations with the Taliban, the government has decided to free Taliban prisoners in exchange for two university professors," Afghan Ghani said.

Ghani said authorities had been unable to pin down the professors’ location. A rescue attempt by U.S. forces failed.

There was no immediate word from the Taliban on when the captives would be released or reaction from the White House. Trump called off a Camp David meeting with the Taliban in September following a suicide bombing that killed a U.S. soldier.