Afghanistan on Tuesday said it would press ahead with the release of scores of alleged Taliban fighters from jail despite US objections that the men were a threat to NATO and Afghan forces.

Kabul announced on January 9 that a total of 72 detainees held at Bagram jail near the capital would be freed due to lack of evidence, sparking strong condemnation from the United States.

Afghan authorities "concluded that the there is no evidence against 72 out of 88 prisoners. We reviewed their cases again after objections by the US forces, and for now we will release 65 prisoners," Abdul Shukur Dadras from the Afghan government body reviewing detainees at Bagram said on Tuesday.

"These 65 inmates... will be released as soon as early next week," he told AFP.

The issue threatens to further strain US-Afghan relations amid pressure for the two countries to sign a long-delayed security deal allowing some American soldiers to stay in the country after 2014.

In a statement, US forces in Afghanistan said the prisoners were a "legitimate force protection concern" for both Afghan and international forces fighting a bloody Taliban-led insurgency since late 2001.

"The release of these detainees is a major step backward for the rule of law in Afghanistan," the statement said.

In Washington, a Pentagon spokesman said American troops would be ready to kill or capture the freed detainees if they posed a danger.

"It is the US position that these are threats to US forces and should they take up arms against us, we would take immediate action," Colonel Steven Warren told reporters.

Asked to elaborate, Warren said that "of course, we would try to kill and capture them as the battlefield situation presents."

Bagram was the main detention centre housing Taliban and other insurgents captured by the Western military forces until it was transferred to Afghan control last year.