Afghan authorities have begun to release 400 Taliban prisoners, AFP reported.

A group of 80 prisoners was released on Thursday, National Security Council spokesman Javid Faisal said, tweeting that it would "speed up efforts for direct talks and a lasting, nationwide ceasefire".

Their release was approved at the weekend by a gathering of thousands of prominent Afghans called by President Ashraf Ghani after the authorities initially refused to free the militants, accused of serious crimes including brutal attacks that killed Afghans and foreigners.

Both sides said they are ready to begin talks in Doha within days of the release of the prisoners.

Among the prisoners, there are about 44 rebels who are of particular concern in the United States and other countries for their role in the attacks.

Ghani warned on Thursday that their release is a "danger" to the world.

"Until this issue, there was a consensus on the desirability of peace but not on the cost of it," Ghani said in a videoconference organised by a US think tank. "We have now paid the major instalment on cost and that means peace will have consequences," he added, noting that the release of "hardened criminals" and drug dealers was "likely to pose a danger both to us and to (America) and to the world".