Jan. 26 (UPI) -- Taliban and U.S. negotiators have made "significant progress" in attempts to end the 17-year war in Afghanistan, the U.S. special representative said Saturday.
Zalmay Khalilzad, a former ambassador to Afghanistan, has held several rounds of talks with the Taliban since he was appointed in September.
He had been negotiating with Taliban representatives from the Taliban's political office in Doha, Qatar.
"After six days in Doha, I'm headed to #Afghanistan for consultations," Khalilzad posted in three messages on Twitter. "Meetings here were more productive than they have been in the past. We made significant progress on vital issues."
Khalilzad, who plans to brief Afghan President Ashraf Ghani, didn't give details of any breakthrough.
"We have a number of issues left to work out. Nothing is agreed until everything is agreed, and 'everything' must include an intra-Afghan dialogue and comprehensive ceasefire," he tweeted.
He also thanked Qatar's government "for their constructive engagement and their facilitation of this round of talks."
Taliban representatives staged a brief walkout over differences with Khalilzad on Friday.
The founding member of the movement and close aide to the first Taliban leader, Mullah Mohammed Omar, will head the Taliban's office in Qatar, the international headquarters for the militant group.
"This has the potential to start the first serious peace process to end one of the biggest wars in the world. It's monumental news, but we're still at the early stages," Graeme Smith, Afghanistan analyst with the International Crisis Group, told The Guardian. "We know the agreement has four parts: ceasefire, counter-terrorism, troop withdrawal, and intra-Afghan negotiations. Sequencing and timelines remain tricky."
In an attempt to get foreign forces to withdraw from Afghanistan within 18 months, the Taliban negotiators reportedly have offered the United States assurances Al Qaeda and Islamic State militants won't attack the United States and its allies in the country.
U.S. President Donald Trump has been considering cutting in half the 14,000 U.S. forces in Afghanistan.
The Taliban controls more than 65 percent of the population, but has authority over just 55 percent of the country's 407 districts.
Last week, Ghani said that 45,000 members of the country's security forces had been killed since he took office in the fall of 2014.
In an area controlled by the Taliban, five people were killed and another 20 injured when an improvised explosive device went off in a volleyball match among young men and boys in Baghlan province Saturday, officials said.
Abdul Ahad Ahmadi, governor of Tala Wa Barfak district, told Turkey's state-run Anadolu Agency the Taliban are responsible for the incident.
The Afghan army said the local commander of Taliban, identified as Mullah Ainouddin, also among the people killed in the explosion and five other Taliban insurgents sustained injuries in the explosion.