Hamas said on Sunday the rival Fatah faction of President Mahmud Abbas is delaying moves to seal reconciliation by insisting on keeping Salam Fayyad as prime minister.
In early May the two sides signed a unity deal in Cairo and have met twice since to discuss the formation of an interim government, but follow up talks with Abbas and Hamas chief Khaled Meshaal have been put on hold.
The talks have reportedly stalled over the prime minister post. Abbas and his Fatah movement want to keep Fayyad, despite strong objections from Hamas.
"The delay in the national reconciliation agreement between Fatah and Hamas stems from our brothers in Fatah," Izzat al-Risheq, member of the Hamas political bureau based in Damascus, told AFP.
"We are waiting for them to come back to the negotiating table to put in place what was planned in this agreement and to make rapid progress on all issues, notably the choice of prime minister," he added.
"No one should create a negative atmosphere lest we find ourselves in a deadlock," he added.
Fatah has officially announced its support for Fayyad as prime minister of an government composed of independents, which must organise elections by May 2012, but Hamas has rejected his candidacy, saying it wants somebody from Gaza.
Palestinian chief negotiator Saeb Erakat said on Wednesday the Hamas-Fatah talks were not in an impasse and that Abbas was "making every possible effort" to form a government.
The reconciliation accord drew criticism from the United States and Israel, which sees the deal as "an obstacle to peace."
However, the United Nations, the European Union and Russia, which with the United States make up the Middle East Quartet, have welcomed the reconciliation deal.