UN Secretary-General Ban Ki-moon has promised Haitians that the world has not forgotten the quake-torn nation as it suffers from a shortage of shelter and growing violence in teeming camps for the homeless.

Security issues and the risk of flooding and disease in the squalid tarp-and-tent cities are pressing concerns for governments and international aid groups struggling to help hundreds of thousands of victims of the January 12 disaster, which killed a government-estimated 230,000 people and left 1.3 million homeless.

Making his second visit to Haiti since the quake, the UN leader met with President Rene Preval and discussed plans for a UN donors conference in New York on March 31 to fund Haiti's reconstruction.

Mr Ban said his message to Haiti's government and people is that "even if time passes, the world has not forgotten. The world is always at their side".

Haiti needs money for schools, infrastructure, roads, ports and electricity, Mr Ban said at a news conference.

And "for the foreseeable future, the government will need international assistance simply to cover its payroll," he said.

A government statement said the tax department expects to collect only a third of its expected annual take of 13 billion gourdes (330 million US dollars). Duties on imports are the government's main source of income.

UN humanitarian chief John Holmes said last week that the United Nations is struggling to raise the 1.44 billion US dollars needed to help earthquake victims this year. Mr Ban said only 49% has been raised.

Mr Ban later toured a makeshift camp where more than 45,000 people are living under a tapestry of blue, orange, white and silver tarps and tents sprawled across a valley golf course -- emblematic of the mixed results of a 2.2 billion US dollar international aid effort.

Behind the tents is a country club that became the base of the US Army's 82nd Airborne Division in the days after the disaster. Only a few soldiers are left, but Mr Ban said the withdrawal of US and Canadian troops "will not compromise the mission."