Serry, the UN special coordinator for the peace process, visited the commission's headquarters in Gaza on Thursday, a statement from his office said.

The commission was due to start updating the electoral roll in Gaza on Tuesday but Hamas canceled voter registration citing the continued arrest of Hamas members in the West Bank and its questions over the commission's impartiality.

Serry said the decision was "very disappointing as both Palestinian reconciliation and the democratic renewal of institutions in the occupied Palestinian territory were long overdue."

He called on those responsible "to reverse the suspension and allow the CEC to resume this vital process without further delay."

The UN official commended the commission's professionalism and independence and congratulated it on its work preparing to register voters in Gaza

In its weekly meeting Wednesday, the Hamas-led government in Gaza called for the reform of the CEC, and said it was "imbalanced."

Hamas leader Mahmoud Zahhar complained Tuesday that the commission was dominated by Fatah members, a claim disputed by CEC director Hisham Kahil who said the Hamas-run Ministry of Education had selected the 500 workers employed to register voters.