KABUL, Afghanistan — The United States and Afghanistan faced potentially divisive issues such as immunity for U.S. troops as the two sides began talks Thursday on a security agreement that will shape America's military presence in the country after the withdrawal of most foreign combat troops in two years.
However, the talks could last up to a year, and questions about specific military operations or the exact number of U.S. troops that will remain in the country were being put off until later, according to a senior U.S. official.
U.S. and Afghan officials also indicated that the issues of legal jurisdiction will be left until later, after easier topics are negotiated. The officials spoke on the condition of anonymity because of the sensitivity of the negotiations.
Earlier this week, Defense Secretary Leon E. Panetta said the Obama administration expected a decision in the next few weeks on how many U.S. troops will remain in Afghanistan after 2014.
He added that Marine Corps Gen. John Allen, the top U.S. commander in Afghanistan, had developed several options but would not reveal what troop levels were being considered.
It is believed that the U.S. wants to retain up to 20,000 troops in Afghanistan after 2014 to train and support Afghan forces and go after extremists and groups, including al Qaeda.
Afghanistan now has about 66,000 U.S. troops, and it remains unclear how many will be withdrawn next year as they continue to hand over security to Afghan forces. The foreign military mission is evolving from combat to advising, assisting and training Afghan forces.
The two countries also are grappling with the potentially divisive issues of whether U.S. troops can be prosecuted under Afghan law -- an issue that nixed America's security deal with Iraq last year -- the U.S. military footprint, and what bases and facilities Americans will use after 2014.
"The negotiations we just started today will be about the quantity, quality and the condition of the presence of American forces in Afghanistan after 2014," Eklil Hakimi, Afghanistan's ambassador in Washington, told reporters after the one-day meeting.
He and James Warlick, the Obama administration's deputy special representative for Afghanistan and Pakistan, are leading the talks, which are expected to resume next month.
"This document is intended to provide the legal authorities of our military forces and its civilian component," Mr. Warlick said.
The decision on troop levels will depend in part on Afghanistan's desire to allow troops to remain and whether the U.S. receives acceptable legal guarantees for American troops.
But the agreement is not expected to be a defense deal, and the senior U.S. official said it would not include a security commitment.
The so-called bilateral security agreement follows a deal that was signed in May in Kabul by President Obama and Afghan President Hamid Karzai -- a document that drew the outlines of the broad relationship between their countries after 2014.
In that deal, the United States said it would work with Afghanistan to develop a response if it was ever attacked, but was not committed to help.
Washington is committed, however, to supporting Afghanistan's social and economic development, security institutions and regional cooperation through 2024. In turn, Afghanistan promised to strengthen government accountability, transparency and oversight and to protect the human rights of all Afghans, both men and women.
Afghanistan and the United States have tried to defuse regional concerns about the agreement. Afghanistan's neighbor, Iran, is opposed to any such agreement.