US secretary of state John Kerry said he did not know whether it was possible to get talks with the Taliban back on track after this week's delays, and warned that the group's new office in Qatar may have to be closed if negotiation efforts failed.
Talks between US officials and representatives of the Taliban had been set for Thursday in Qatar but Afghan government anger at the fanfare surrounding the opening of the Taliban office in the Gulf state threw preparations into confusion.
"We need to see if we can get back on track ... I don't know whether that's possible or not," Kerry told a news conference in Qatar.
"If there is not a decision ... to move forward by the Taliban in short order, then we may have to consider whether or not the office has to be closed," he added.
The opening of the Taliban office was a practical step paving the way for peace talks to end Afghanistan's 12-year-old war.
But the official-looking protocol surrounding the event raised angry protests in Kabul that the office would develop into a Taliban government-in-exile. A diplomatic scramble ensued to allay the concerns.