Talks to end the 18-year-old conflict in Afghanistan may begin this month, Reuters reported sources as saying on Monday, a day after the US special envoy visited Islamabad and met Taliban leaders in Qatar.

The Taliban’s spokesman Suhail Shaheen tweeted that US envoy Zalmay Khalilzad had discussed “the commencement of intra-Afghan negotiations” with the insurgents’ political leaders in Doha on Sunday. Khalilzad had earlier met Pakistan’s army chief of staff, according to the US Embassy in Islamabad.

Washington signed a troop withdrawal deal with the Taliban in February, but its attempts to start peace talks between the insurgents and the Afghan government have been mired in setbacks and violence surged in March and April.

Kabul sources were quoted as saying that those issues were gradually being resolved and “momentum had grown” in recent weeks for formal intra-Afghan talks, which were expected to begin this month, likely in Doha.