James Dobbins, who is on a regular visit to Kabul, told The Associated Press he met with Karzai and mostly discussed reconciliation efforts with the Taliban, which the American diplomat said remain stuck because the insurgents don't want to talk.
"On the security agreement we really did not make any progress. It was a restatement of the known positions. I explained why we thought it was important to remove the anxiety and uncertainty around this as quickly as possible," Dobbins said.
Instead, Karzai wants his successor to decide after the April 5 elections. He also has indicated that he will not sign any agreement that allows for continued air strikes and foreign raids on Afghan homes.
Civilian deaths at the hands of US and allied soldiers have been a key source of contention, exacerbated last week by a US drone strike that killed a child.
Military planners need the time to prepare for a post-2014 mission that could involve around 8,000 American and 6,000 allied troops.
Also at stake is more than USD 8 billion in annual international military and development aid planned for Afghanistan after 2014.
Dobbins said that the "longer we postpone this, the more of that support we are going to lose. The coalition will begin to fragment, the amount of assistance that will be committed will start to erode, and so I felt we really can't afford to delay this much longer."
