The U.S. special envoy for Afghanistan, Zalmay Khalilzad, has held a new round of talks in Qatar with the Taliban's political chief.
Mullah Abdul Ghani Baradar, a spokesman for the militants, said on Twitter late on June 7 that Khalilzad and Baradar discussed the release of prisoners and the start of intra-Afghan talks.
In February, the United States and the Taliban signed an agreement aimed at ending the 18-year war -- the longest military conflict in U.S. history. The deal lays out a timetable for the withdrawal of U.S. troops from Afghanistan in return for security commitments from the Taliban.
It also stipulates that Kabul must free 5,000 Taliban prisoners, while the militants are to release 1,000 captives -- a move expected to lead to intra-Afghan negotiations.
Separately, Khalilzad met with Pakistani Army chief General Qamar Javed Bajwa on June 7, the U.S. Embassy in Islamabad and the Pakistani military said.
Both sides discussed "steps required for the start of intra-Afghan negotiations," the embassy said in a statement on June 8.
Pakistan and Afghanistan have had strained ties for years. Kabul has long accused Islamabad of providing safe haven to Taliban militants who launch attacks against international and Afghan forces.
Pakistan last week appointed a new special envoy to Afghanistan in a fresh bid to improve bilateral relations.
Muhammad Sadiq Khan previously served as Pakistan's ambassador to Afghanistan from 2008 to 2014.
Khan, a former spokesman for the Foreign Ministry, would play "an effective role in strengthening ties" between the two neighbors, according to a statement by Pakistan's Foreign Ministry.