The talks, scheduled for Friday between Afghan government and Taliban representatives, were considered a significant first step towards finding a negotiated end to the war in Afghanistan and the eventual withdrawal of United States troops, which would end the US's longest war.
Sultan Barakat, director of the Center for Conflict and Humanitarian Studies in Qatar, which had been facilitating the meeting, said there was no disagreement about the agenda.
The militant organisation now controls or influences about half the country, and past year was the deadliest yet for civilians. In a statement, the presidential palace said Qatar had rejected the long list of delegates and suggested a shorter one which was "not acceptable".
"Clearly, the moment is not yet right", he added.
The Taliban did not immediately comment but Taliban spokesperson Zabihullah Mujahed on Wednesday questioned the size of the government delegation, saying it was not "normal" and that they had "no plans" to meet with so many people.
"The Qatari government sent a new list which was not balanced in terms of involvement of the people of Afghanistan ... it was a disrespect to the national will of the Afghan people", the statement said.
The creators of Kabul list must realize that this is an orderly and prearranged conference in a far-away Khaleeji country and not an invitation to some wedding or other party at a hotel in Kabul.
The Taliban had previously refused to hold direct talks with Ghani's government, calling them puppets of the US.
Kabul blamed the Qatari government for the summit´s derailment.
The conference "mess and its dysfunction amplifies just how much of a long, hard slog a reconciliation process will be", he told AFP.
Even some of those Ghani said would attend dropped out, slamming the guest list as rigged to politically strengthen the president, who faces delayed elections in September.
The meeting would have been the first of its kind since the Taliban was ousted from power by a US-led coalition in 2001, and came amid pressure from Washington to find a diplomatic solution to hostilities.
US Special Representative to Afghanistan Zalmay Khalilzad said he was "disappointed" the summit had been postponed.
"I urge all sides to seize the moment and put things back on track by agreeing to a participant list that speaks for all Afghans".
The Taliban responded to the news in a statement, saying that it remained committed to peace talks in Doha, blaming Kabul for the failure of the meeting.