UN Secretary-General Ban Ki-moon speaks to reporters at UN headquarters in New York, the United States, Jan. 15, 2010. The United Nations on Friday issued a flash appeal of 550 million U.S. dollars to provide emergency care to thousands of Haitians suffering from the fallout of Tuesday's earthquake that has devastated the country and created an epic humanitarian challenge. [Xinhua]

UN Secretary-General Ban Ki-moon announced Friday that he will soon travel to Haiti, which was devastated by a massive earthquake earlier this week, to show solidarity with the people of the impoverished Caribbean nation.

The secretary-general plans the trip at a time when the United Nations continues to rush aid to the victims. The 7.0 magnitude earthquake is said to have affected one-third of Haiti's 9-million strong population. Many of the people in the hard-hit capital, Port-au-Prince, do not have access to food, water, shelter and electricity.

UN emergency teams on the ground estimate that as many of half of the buildings in the worst-hit areas of the capital have been damaged or destroyed.

"We are still in the search-and-rescue phase, and we are trying to save as many lives as possible," Ban told reporters at the UN Headquarters in New York on Friday.

With the top UN official in Haiti, Hedi Annabi, still unaccounted for, Ban dispatched Edmond Mulet, his former special representative to Haiti and current Assistant-Secretary-General for Peacekeeping Operations, to the country to assume full command of the UN Stabilization Mission (MINUSTAH).

Upon arriving in Port-au-Prince on Thursday, Mulet held talks with Haiti's leaders, in which he stressed that MINUSTAH is in the process of building back its capacity and emphasized the UN mission's full support of the government as it rebuilds the devastated capital.

UN Secretary-General Ban Ki-moon speaks to reporters at UN headquarters in New York, the United States, Jan. 15, 2010. [Xinhua]

The secretary-general announced that he is also sending Tony Banbury, the UN assistant-secretary-general for field operations, to serve as Mulet's deputy.

"I myself will go to Haiti very soon, both to show solidarity with the people of Haiti and our UN staff and to assess the situation for myself," Ban said.

A major humanitarian operation is under way, he said, and "although it is inevitably slower and more difficult than any of us would wish, we are mobilizing all resources as fast as we possibly can."

With the airport's capacity limited, roads still blocked and the lack of transport and fuel within Haiti, the logistical situation, the secretary-general said, is a very difficult one.

"That said, the international community's response has been generous and robust, and we are gearing up rapidly and effectively despite the challenging circumstances," he said.

The United Nations will launch a flash appeal for some 550 million U.S. dollars this afternoon, with a bulk of these funds to be directed to urgent needs, including food, water and shelter.

UN spokesperson Martin Nesirky announced here Friday that over 300 UN personnel are still missing or unaccounted for, with 36 military and civilian MINUSTAH personnel, as well as one staff member with the UN World Food Program (WFP), having been confirmed to have died.

The Christopher Hotel, which houses the UN headquarters in Haiti, and other buildings hosting the world body's offices collapsed in the tremors.