President Hamid Karzai's office made the announcement following talks with some of Afghanistan's most senior justice, defence and intelligence officials.

"The transition of Bagram prison to Afghan authority is a great success for Afghanistan therefore a splendid ceremony has to take place on September 10 for its full handover," the palace announced.

A NATO military spokesman in Afghanistan said he was "aware of the statement" but made no other immediate comment.

Afghanistan and the United States signed an agreement on March 9 beginning a six-month transition from American to Afghan control of the jail north of Kabul and just outside Bagram, the largest US military base in the country.

The handover had been a key sticking point to concluding a pact, which would likely cover the legal status of US troops who remain in Afghanistan long-term to help the government fight the Taliban.

Karzai had demanded that the prison be transferred before signing any deal governing Afghan-US relations after NATO combat troops pull out in 2014.

In Iraq, Washington pulled out all its troops after failing to get Baghdad to grant its soldiers legal immunity.

The prison, which has sometimes been called Afghanistan's Guantanamo Bay, holds rebel fighters detained by US-led NATO forces in their decade-long war against the Taliban-led insurgency trying to topple Karzai's government.

Under the agreement, Afghan authorities will need to advise the United States of plans to release any prisoners and "consider favourably" objections if the Americans consider such inmates could engage in "terrorist activity".

US officials would also remain at the prison to provide advisory, technical and logistical support for a year.