The latest round of talks with the Taliban — now in their second week and paused for two days — has been “very productive,” a US negotiator said, and denied Washington sought a fixed deadline for the withdrawal of its estimated 14,000 troops from Afghanistan as part of a final peace deal in the 17-year-old war.

The talks are being paused while another summit with Afghan representatives takes place, a Taliban spokesman said on Saturday.

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.

Negotiations picked up momentum after US Secretary of State Mike Pompeo visited Afghanistan's capital, Kabul, at the end of last month. He said then that Washington was hopeful of an agreement before September 1.

The appointment last year of Zalmay Khalilzad as US special peace envoy began the accelerated effort to find a negotiated end to Afghanistan's war and America's longest military engagement.

Since then, Khalilzad has held scores of talks with the Afghan government in Kabul and abroad, with the Taliban as well as with Afghanistan's neighbours including Pakistan.

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The Taliban have refused to talk directly with Kabul, considering it a US puppet. The insurgents, however, say they will sit down with any Afghan, even a government official, but as an ordinary citizen and not as a government representative.

The Taliban currently control nearly half of Afghanistan, and are more powerful than at any time since the 2001 US-led invasion.

More than 2,400 US service personnel have died in Afghanistan since the US-led coalition invaded in October 2001 to oust the Taliban and hunt down al-Qaida chief Osama bin Laden following the September 11, 2001, attacks on the United States.

The US official in Qatar's capital, Doha, where the Taliban maintain a political office and where talks are being held, told The Associated Press on Friday that the US “definitely did not offer” an 18-month withdrawal as part of a peace deal. That's the time frame that Taliban officials gave the AP months ago.

The official spoke anonymously because of the sensitivity of the talks.

The US negotiator said the deal being negotiated in Doha with the Taliban is “comprehensive and includes specifics on all four parts including a cease-fire, timeline, participating in intra-Afghan negotiations and counter-terrorism assurances.”

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On Saturday, several prominent Afghan figures left Kabul for Doha ahead of much-anticipated all-Afghan talks to begin Sunday. The talks are co-sponsored by Germany and Qatar, and include the Taliban.

An earlier round of intra-Afghan talks, which were to be held last April, were scuttled after the two sides could not agree on participants. The Afghan government had submitted a list of 250 people. The Taliban likened it to a wedding party.

This time the Taliban say 60 people will participate.

Attaullah Rahman Salim, the deputy head of the government's high peace council, said 64 would be sitting around the table.

The list includes former mujahedeen who fought the Soviet in the 1980s as well as former government officials, former ambassadors, civil society representatives and a small number of women.

Participants at the table will be there as ordinary Afghans “on equal footing” and not as government representatives, said the German sponsors.

Afghan President Ashraf Ghani, who has been conspicuously quiet about the upcoming intra-Afghan dialogue, has consistently demanded Taliban talk directly with the government.