Afghanistan's presidential election will be postponed by three months to July 20 to give authorities more time to organize the ballot, election authorities announced on Sunday, following mounting speculation of a delay.

The announcement follows heavy criticism of October's chaotic parliamentary election, which saw problems ranging from roadside bomb attacks to malfunctioning biometric voter verification equipment, incomplete voter lists and huge delays at polling sites.

The timing of the election has also been complicated by talks under way between U.S. special envoy Zalmay Khalilzad and representatives of the Taliban aimed at launching a full peace process to end the war in Afghanistan.

The election was originally scheduled for April 20 but Gula Jan Abdul Bade Sayad, chairman of the Independent Election Commission (IEC) said mounting problems had forced a delay.

"April will be very difficult because of the harsh winter and transporting election materials, security, and the budget issues", Sayad told a news conference in Kabul.

"To better prepare for the vote, we have decided to hold the election in July next year," he added.