Abbas and Hamas chief Khaled Meshaal met on Sunday in the Qatari capital to finalise issues arising from a reconciliation agreement signed by the two factions last April.
They are expected to meet again on Monday with a formal announcement expected later in the day.
The official said Hamas and Abbas's secular Fatah movement had agreed that the "national consensus government will be made up of independents and technocrats and they will be responsible for overseeing the elections."
He did not say when the elections would take place but under the terms of the reconciliation deal parliamentary and presidential elections are both to be held by May.
Implementation of the deal has been delayed on several occasions despite repeated meetings between the two parties but on Sunday they agreed to move speedily ahead with the elections.
"We agreed on the importance of holding the elections quickly ... and removing any obstacles that might delay the polls," said Fatah spokesman Azzam al-Ahmad, who is accompanying Abbas in Doha.
He said Sunday's talks, which are being hosted by Qatar's emir, Sheikh Hamad bin Khalifa Al-Thani, were "positive" and that both sides reached "agreement on all the major issues" regarding the reconciliation agreement.
The last Palestinian elections were held in 2006.