DOHA, Qatar — The first talks between Afghan leaders and Taliban insurgents, scheduled to begin here Friday, were abruptly postponed Thursday amid an eruption of internal disputes and Taliban complaints over the size and composition of the Afghan government delegation.

It was not clear how soon the talks would be rescheduled, but some Afghan officials said a small group might travel to the Qatari capital from Kabul on Friday, while efforts continued to pare down and reconfigure the full list of 250 delegates from across Afghan society that was announced by the government Tuesday.

The planned meeting in Doha has been widely hailed as a potential first step toward peace talks between the Taliban insurgents and their fellow Afghans. The Taliban has long refused to recognize the Kabul government while holding peace discussions with U.S. officials in this Persian Gulf sheikhdom. Now, the eagerly awaited intra-Afghan talks have fallen into question amid acrimony and disarray.

One aide to President Ashraf Ghani, speaking on the condition of anonymity because of the sensitive topic, said the trip was delayed because the Taliban representatives and their host, the government of Qatar, wanted some individuals removed from the delegation “in order to make it weak.”

Meanwhile, some delegates voluntarily withdrew Thursday from the planned talks, including one senior Afghan official who expressed anger at Taliban statements ridiculing the Afghan delegation and accused the insurgents of trying to sabotage the talks.

“Taliban are the only & the biggest obstacle to peace as they continue the campaign of massacre & destruction,” tweeted Amrullah Saleh, a former intelligence chief who is now Ghani’s running mate in a presidential election scheduled for September. Saleh said the Taliban “should agree to direct & focused negotiations with the Afghan government.”

Several other delegates, reached by phone in Kabul, said they still planned to attend any talks but complained of poor management by Ghani’s peace team and excessive demands by the Taliban. The Taliban insisted that any Afghan officials participate only as private individuals so as not to confer legitimacy on a government the insurgents call an American puppet regime.

On Wednesday, after the delegation was announced, the Taliban ridiculed it as far too large and poorly organized. In a statement, a Taliban spokesman said the group’s meetings with U.S. officials had been “orderly” and well planned, while the sprawling Afghan delegation seemed more like an “Afghan wedding or other party in Kabul.”

One delegate, a political activist named Mohammad Idrees Stanikzai, said the Taliban is trying to weed out delegates who were “vocal critics of their wrongdoings” during the five years of repressive Taliban rule from 1996 to 2001. He said many young Afghans want an “Islamic republic, not an Islamic emirate,” or religious government. “We will defend our rights, and we will ask them to join the system.”

There were conflicting reports Thursday that officials in Kabul were working to cut down the list, which grew from about 50 to 250 as more and more political and civic leaders demanded to be included. Several sources said the list has now been cut in half, but a senior government aide said that only a few people have dropped out on their own.

“We wanted a small team, but it kept growing because so many people wanted to go,” said the aide, who spoke on the condition of anonymity to discuss internal matters. “It may not be a perfect team, but it represents a broad consensus across the Afghan state. Now the ball is in the Taliban’s court.”

The U.S.-led talks with Taliban officials, which began several months ago, have completed five rounds without any major progress. The insurgents’ priority is the withdrawal of all foreign troops, and until now the group has refused to meet formally with any Afghan officials, although it did interact with some Afghan leaders at a meeting in Moscow.

Many Afghans have expressed fears that U.S. haste to reach a deal with the Taliban would sacrifice their concerns about future political and social rights if the Taliban regains a measure of power. The main goal of the intra-
Afghan meeting planned for Friday, and now in limbo, was to express those concerns directly to the Taliban.

Sayed Salahuddin and Sharif Hassan in Kabul contributed to this report.