The latest round of US-Taliban talks ended in Qatar on Thursday, an insurgent spokesman said, after "positive and constructive" negotiations that continued even as the Taliban bombed a US-funded aid group in Kabul.

File photo: VCG

Suhail Shaheen, the Taliban's political spokesman in Doha, tweeted that "some progress" had been made at the sixth round of peace talks and that the foes would meet again for another round of discussions.

"In general, this round was positive and constructive. Both sides listened to each other with care and patience," Shaheen wrote on Twitter. 

The US embassy in Kabul did not immediately comment, nor did US peace envoy Zalmay Khalilzad, the Afghan-born former US ambassador to Afghanistan who is leading negotiations for the Americans.

Shaheen told AFP Sunday that peace negotiations were stumbling over the fundamental question of when foreign forces would depart Afghanistan.

Before the US agrees to any withdrawal as part of an eventual deal, it is demanding the Taliban put in place security guarantees, a ceasefire and other commitments including an "intra-Afghan" dialogue with the Kabul government and other Afghan representatives.

The Taliban however insist they won't do any of these things until the US announces a withdrawal timeline.

At the end of a large peace summit in Kabul last week, President Ashraf Ghani offered the Taliban a ceasefire to begin on the first day of Ramadan, but the insurgents refused.

On Wednesday, a Taliban suicide bomber and four gunmen attacked Counterpart International, a non-profit group working with marginalised people in Afghanistan, killing nine people. 

"This violent attack is a senseless assault on the noble values that the organisations like Counterpart support, such as service to others, education, and inclusion," US Secretary of State Mike Pompeo said in a statement.