A meeting at the Nato summit on the alliance’s plans in the country ended with no agreement on setting up a new training mission because of political paralysis in Kabul over the contested presidential election.
Western officials said talks to keep up to 12,000 troops, including more than 9,000 Americans, as trainers and advisers had effectively stalled.
Afghanistan cannot sign a security pact agreeing to the mission until it has appointed a new president. Two candidates are awaiting the result of a delayed and acrimonious vote audit after allegations the poll was marred by rampant ballot stuffing.
Anders Fogh Rasmussen, Nato’s secretary general, said: “Without a signature, there can be no mission.
He said: “Although the military planners have shown great flexibility in their planning, time is short and the sooner the legal framework is in place, the better.”
But without a security deal which allows troops and advisers to see how the money is being spent, officials said donors were likely to be very reluctant to commit.
Mr Rasmussen said: “We will need to know where our money is going and how it is being spent.”