President Hamid Karzai is unlikely to sign a pact for US and Nato forces to stay in Afghanistan after this year and will probably leave the choice for his successor, Nato chief Anders Fogh Rasmussen said.
Kabul and Washington spent months negotiating a legal framework for some US troops to stay on after the end of the year when Nato-led forces are due to end combat operations, leaving behind a much smaller training and advisory mission.
But Karzai has said he will not sign the agreement unless certain conditions are met.
The delay has frustrated the United States and its allies, who want to plan the post-2014 training and advisory mission.
Both the United States and Nato have said they may be forced to pull their forces out of Afghanistan entirely at the end of this year unless the agreement is signed soon. Rasmussen acknowledged for the first time on Saturday that he did not expect Karzai to sign the US pact and a similar pact that must be negotiated with other Nato forces.
The Nato-led force currently has about 57,000 soldiers in Afghanistan, two-thirds of them from the United States. Troop numbers are expected to fall to 8,000-12,000 after this year.