The insurgents have been meeting with US peace envoy Zalmay Khalilzad in Qatari capital Doha to try to forge a deal that would see the US military quit Afghanistan in return for various guarantees.

Suhail Shaheen, the spokesman for the Taliban's office in Qatar, said they were pleased with progress in the talks.

"Tomorrow and the day after, because of the intra-Afghan conference, no talks will take place," Shaheen tweeted, referring to separate talks due to start Sunday in Doha between the Taliban and Afghan delegates.

"We are happy with progress and hope the rest of the work is also done. We have not faced any obstacles yet," he added.

Neither Khalilzad nor the US State Department immediately commented.

About 60 Afghan delegates are expected to attend Sunday's so-called intra-Afghan dialogue, including political figures, women and various Afghan stakeholders.

The Taliban, who have steadfastly refused to negotiate with the government of President Ashraf Ghani, have stressed that those attending will only do so in a "personal capacity".

But the US has made it clear the Taliban must talk with the Afghan government before a peace deal can be completed. US Secretary of State Mike Pompeo has said he hopes for an agreement before September 1.