A woman stands in a makeshift tent camp for earthquake survivors in Port-au-Prince on Feb. 5. (Ramon Espinosa/Associated Press)The United Nations is asking for nearly $1.44 billion US to help the three million Haitians affected by last month's earthquake, the organization's largest appeal ever for a natural disaster.

The appeal to cover Haiti's needs in 2010 is more than double the UN's initial request on January to aid the country over a six-month period.

"Before last month's disaster we had a plan for Haiti's long-term development and reconstruction," UN Secretary-General Ban Ki-moon said Thursday. "Our challenge today is to reformulate that plan to help Haitians build back better."

Ban and his special envoy for Haiti, former U.S. president Bill Clinton, made the appeal Thursday at a meeting of diplomats from many of the 191 UN member states.

Donors have already pledged $673 million US for relief, according to a spokeswoman for the UN Office for the Co-ordination of Humanitarian Affairs.

Aid workers say more is needed

The United Nations' top humanitarian aid official, John Holmes, said progress has been made since a massive earthquake struck the Caribbean nation on Jan. 12, killing more than 200,000 people and levelling 38 per cent of the capital of Port-au-Prince, including nearly every government ministry.

But Holmes said much more work needs to be done, particularly since the rainy season is expected to cause further devastation to the 1.2 million people living in Port-au-Prince streets.

"What we still need to do is go further and faster on areas like shelter, like tents — so people have got some cover over their heads against the rain — and sanitation to prevent the spread of disease," he said.

Haitian Prime Minister Jean-Max Bellerive walks away after being greeted by Canadian Foriegn Minister Lawrence Cannon during a conference on Haitian reconstruction in Montreal on Monday. (Canadian Press)

Rubble removal is also important, particularly in the capital, he said, because it frees more space for people to live in what is already a crowded city.

Haiti PM calls for end to infighting

The appeal for more aid comes as Haitian Prime Minister Jean-Max Bellerive expressed concern that his government could face collapse over its inability to handle the crisis.

Bellerive, the nation's second-in-command to president Rene Preval, told The Associated Pres that infighting over the relief effort could undermine the government and its ability to deal with the crisis.

"You have the feeling that everyone is trying to do his little part and accuse the other one of not doing his part," he said. "Everyone is trying to create conflict when we have the same enemy right now: It's misery, it's disaster."

A legislative election scheduled for this month has already been cancelled because of the disaster, and a presidential election scheduled for later in 2010 is also in question. Bellerive said the potential for a constitutional challenge to the government's legitimacy could undermine relief efforts during a critical time.

"I am not asking for a truce, but I believe we have a serious problem that we have to face right now as a nation," Bellerive said.

With files from The Associated Press