U.S. Secretary of State John Kerry is in Afghanistan for urgent talks with Afghan President Hamid Karzai, reported Associated Press on Friday.
The completion of a security deal to allow American troops to remain in Afghanistan after the end of the NATO-led military mission next year will be the main topic of discussion.
The original deadline for the deal was the end of October.
Kerry's unannounced visit to Kabul comes as talks on the Bilateral Security Agreement have foundered over certain important issues.
These issues include the problem of Afghan sovereignty despite a year of negotiations.
The U.S. wants a deal by the end of the month, with any remaining troops able to conduct counterterrorism and counterinsurgency operations.
However, the discussions have stalled over Karzai's demand for American guarantees against future foreign intervention, a veiled reference to neighboring Pakistan.
The rebuilding of war-torn Afghanistan began in 2002, following the U.S.-led invasion one year earlier.