Afghan traditional leaders will meet next week to decide whether to support a security pact that could allow some US troops to stay in the country after 2014, an official said Tuesday.

Around 2,500 tribal elders and other civilian leaders are expected to take part in the "loya jirga" starting November 21 to decide whether to accept the draft Bilateral Security Agreement between Afghanistan and the US.

"The loya jirga in which 2,500 people from different catagories participate will be held next Thursday," Abdul Khaliq Hussieni Pashaee, a spokesman from the jirga preparation commission, told AFP.

"We have finalised the lists and all preparations are complete, the delegates are going to start coming to Kabul in a couple of days," he said, adding the jirga was expected to last four days.

The draft pact was hammered out in Kabul last month by the US Secretary of State John Kerry. But he left without a final deal as Afghan President Hamid Karzai said only a jirga had the authority to decide on contentious issues.

These include a US demand to retain legal jurisdiction over its troops in Afghanistan, which would give them immunity from Afghan law. The request emerged as the main sticking point after Kerry's visit.

If the agreement is passed by both loya jirga and parliament, between 5,000 and 10,000 US troops would stay in Afghanistan to help fight Al-Qaeda remnants and train the national army.

The collapse of a similar security agreement with Iraq in 2011 led to the US pulling all its troops out of the country, which is currently suffering its worst sectarian violence since 2008.

On Monday the Taliban, whose government was toppled by a US-led invasion in 2001, warned members of the assembly they would be punished as "traitors" if they endorsed the deal.

Washington had been pushing for the agreement to be signed by the end of October to allow the US-led NATO coalition to plan the withdrawal of its 87,000 combat troops by December 2014.