US Secretary of State John Kerry insisted Thursday that any American troops left in Afghanistan after international combat forces withdraw in 2014 will remain under Washington's jurisdiction.

Fresh from negotiating a bilateral security deal with Afghan President Hamid Karzai last week, Kerry however again rejected the notion that such a move would give US soldiers legal immunity from prosecution if they committed any crimes.

In two days of talks in Kabul, the two men reached a deal that now has to be approved by Afghanistan's council of public and tribal leaders known as a "loya jirga."

"Everything that will be necessary to a successful agreement is in the agreement. We succeeded in defining exactly what the limits would be for American participation in the future," Kerry told National Public Radio.

The Afghans still have to agree, however, whether any American troops accused of crimes would be tried by US or Afghan courts.

"Needless to say, we are adamant it has to be the United States of America. That's the way it is everywhere else in the world," Kerry said.

"And they have a choice: Either that's the way it is or there won't be any forces there of any kind."

But he stressed the deal "doesn't mean that anybody's immune."

"We recently tried a soldier who murdered a number of people in Afghanistan. He was tried and found guilty."

Army Sergeant Robert Bales, who was convicted of murdering 16 Afghan villagers in a horrific rampage in March 2012, was sentenced to life imprisonment in August with no parole by a six-member US military panel at Joint Base Lewis-McChord, in Washington state.

Kerry told NPR he believed the Afghan people and parliament would back the deal, saying: "I believe they understand that this agreement is in the interests of Afghanistan, because it's an agreement that provides for international support, not just the United States."

Washington wants the security deal signed within weeks to enable the NATO military coalition to plan its withdrawal of 87,000 combat troops from Afghanistan by December 2014.

A similar US security agreement with Iraq in 2011 collapsed over the issue of troop immunity.

The US pulled its troops out of the country, which is currently suffering its worst sectarian violence since 2008.