A ceremony to mark the complete transfer of a controversial jail from US to Afghan control was cancelled on Saturday, another setback in a long-running dispute over detainees.
The event at Bagram prison had been announced by Afghan President Hamid Karzai, who said it would mark the successful culmination of years of work to decide the fate of suspected militants held by US forces.
But the transfer was abruptly cancelled on the same day that a suicide bomber killed nine people outside the defence ministry in central Kabul during a visit to the Afghan capital by new US Defense Secretary Chuck Hagel.
"We intend to proceed with the transfer once we have reached full agreement," a spokesman for the NATO-led international coalition said in a statement.
Mohammad Zahir Azimi, spokesman for the Afghan defence ministry, said the transfer "had been postponed due to technical reasons".
Karzai said this week that after the transfer he would order the release of any innocent detainees even though he expected to face criticism.
US officials have suggested that some released detainees return to the battlefield, and there are fears that the government is freeing suspected militants to help kick-start peace talks with the Taliban.
Last September the United States gave Afghan authorities custody of more than 3,000 detainees at Bagram, a sprawling detention centre 50 kilometres (30 miles) north of Kabul.
But the Americans continued to guard 50 foreigners not covered by the agreement as well as hundreds of Afghans arrested since the transfer deal was signed in March 2012.
Kabul made control over the prison a condition for signing a long-term agreement that would allow some US troops to remain in the country after the bulk of Western combat forces withdraw next year.