UN Secretary-General Ban Ki- moon on Thursday voiced dismay at continued disruption of the normal functioning of the UN office in Sri Lanka's capital Colombo, describing the current situation as "unacceptable."

"The Secretary-General finds it unacceptable that the Sri Lankan authorities have failed to prevent the disruption of the normal functioning of the United Nations offices in Colombo as a result of unruly protests organized and led by a cabinet minister of the government," UN associate spokesman Farhan Haq told reporters.

"In light of the evolving situation, Ban is recalling the UN resident Coordinator Neil Buhne to New York for consultations," Haq said.

The Secretary-General has also decided to close the UN Development Program (UNDP) Regional Center in Colombo, he said.

"The Secretary-General calls upon the Government of Sri Lanka to live up to its responsibilities towards the United Nations as host country, so as to ensure continuation of the vital work of the Organization to assist the people of Sri Lanka without any further hindrance," he added.

Some 200 people work at the UN Development Program (UNDP) Regional Center in Colombo, which houses the main offices of various UN functions in Colombo.

The protests in front of the UNDP regional center, which began on Tuesday, escalated on Thursday with Engineering Services Minister Wimal Weerawansa commencing a death fast.

The cabinet minister who organized the protests is demanding the abolition of a UN advisory panel on alleged war crimes during the last stages of the island's military conflict with Tamil Tiger rebels.

The United Nations had expected that its essential staff would be able to return their Colombo office on Thursday.

The Sri Lankan government said Thursday that it is seeking a rapid end to the crisis resulting from the protest outside the UN office in Colombo.

However, Foreign Minister G. L. Peiris said the government will not obstruct any peaceful protest.