A minute of silence was planned for Tuesday at 4:53 pm (2153 GMT) at UN headquarters in New York to mark the time the magnitude-7 earthquake struck Haiti a week ago, dpa reported.
UN Secretary General Ban Ki-moon was scheduled to lay a wreath in honour of the quake victims, and a minute of silence was to be held throughout the UN system, the UN said.
The ceremony in the meditation room of the UN General Assembly lobby will be attended by the UN leadership and some staff. The UN said a candlelight vigil was also planned in the plaza north of the UN compound following the ceremony.
The UN peacekeeping mission in Haiti was hard hit by the quake, with some 46 staffers confirmed dead as of Monday and over 500 still unaccounted for. It was the largest-ever loss of life during a UN mission.