KABUL, Oct 11 (Reuters) - U.S. Secretary of State John Kerry arrived in Afghanistan on Friday to advance negotiations with President Hamid Karzai on a bilateral security pact which have hit a wall over two issues that have become deal breakers for the Afghan government.
The United States says it wants the deal done by the end of October, while Karzai has declared it can wait until after presidential elections in April next year, further straining what has become a rocky relationship between the allies.
U.S. officials, speaking en route to Kabul, said Kerry's visit was not intended to close a deal on the Bilateral Security Agreement (BSA).
"This is really about us building momentum for the negotiators and helping establish conditions for success of the negotiations going forward," a senior State Department official told reporters.
The deal will determine the presence of U.S. forces in Afghanistan after most are withdrawn in 2014 and a failure to reach an agreement could prompt Washington to pull out all forces, an outcome known as the "zero option".
"The ball remains in the Afghans' court... Time is of the essence, the longer it goes, the harder it is to plan," said a second State Department official.
Talks over the pact have stalled over two points.
One is a U.S. request to run independent counter-terrorism missions on Afghan territory, which have long infuriated Karzai. The Afghans instead want the United States to pass on information and let them handle the action.
The second sticking point is a U.S. refusal to guarantee protection from foreign forces as it could lead to offensive action against another ally, neighbouring Pakistan.
The collapse of similar talks between the United States and Iraq in 2011 - sparked partly by Iraq's refusal to provide immunity to U.S. soldiers serving there - led to the United States pulling its troops out of the country.