United Nations - A senior UN official warned Friday amid escalating violence in East Timor that peace in the former Portuguese colony was a "prerequisite" for a UN-organized ballot.

"Clearly it's not possible to hold these consultations in an atmosphere charged with fighting, that has to stop," UN special representative Jamsheed Marker told reporters here after holding talks with leading East Timor resistance leader Jose Ramos-Horta.

"And that's a prerequisite. It's something that we've told all sides, and in particular the Indonesian government, and they're aware of that," Marker said. Marker said that he was concerned about the pre-poll violence, but not surprised.

Marker, who on Friday also met with the Portuguese and Indonesian ambassadors to the United Nations, said there was "no turning back" in the process that is expected to lead to East Timor independence by the end of the year.

He said that Indonesian Foreign Minister Ali Alatas had assured him on Wednesday that Indonesia hoped to bring a finalized draft autonomy package to talks here with Portugal on April 21.