A meeting between the Taliban and Afghan politicians and civil society aimed at ending more than 17 years of war in Afghanistan has been postponed, officials and diplomats said on Thursday, citing Taliban objections to the size of the Afghan delegation.

The talks were set to begin on Friday in Doha, but a senior government official in Kabul said “the gathering has been called off for now and details were being reworked.”

Afghan delegates scheduled to fly to the Qatari capital on Thursday were told the trip was postponed and new dates were being discussed, a western diplomat in Kabul said.

“The government will have to change the composition of the delegation to make this meeting happen,” the diplomat said on condition of anonymity.

Taliban spokesman Zabihullah Mujahid said leaders of the hard line Islamist group were uncomfortable with the size of the Afghan delegation and its composition.

“Presence of some participants was completely against the list of what was agreed upon,” Mujahid told Reuters over phone, adding that the delegation included Afghans working for the government.

The Taliban have repeatedly refused to meet President Ashraf Ghani’s government, which they call a puppet regime, but have held several rounds of peace talks with US officials.

Ghani said Wednesday the 250-member Afghan delegation included some government officials attending in a personal capacity. But the group did not include some of the most powerful figures in Afghan politics, who are reluctant to join forces with Ghani ahead of presidential elections due in September.