The World Bank has said it will provide an additional $100m in emergency aid to Haiti as governments and aid groups step up efforts to help the Caribbean country in the aftermath of Tuesday's devastating earthquake.
The pledge comes as the Red Cross said it estimated that at least three million people are in desperate need of urgent assistance, including search and rescue teams, medical supplies, shelter, food, and clean water.
The Haitian government has said it believes the magnitude 7.0 quake may have left over 100,000 people dead.
"This is a shocking event and it is crucial that the international community supports the Haitian people at this critical time," Robert Zoellick, the World Bank president said in a statement on Wednesday.
"The World Bank is mobilising significant financial assistance and sending a team to help assess damage and reconstruction needs. Our thoughts are with the people of Haiti, our staff, and our UN colleagues."
Dominique Strauss-Kahn, the head of the International Monetary Fund, the World Bank's sibling institution, said it also plans to lend support.
On Tuesday, the Inter-American Development Bank (IADB), another Washington-based institution, announced that $200,000 for emergency assistance would be provided with more funds to be made available if needed.
The US government meanwhile has also begun to mobilise a massive military effort in response to the disaster, readying ships, helicopters, transport planes and a 2,000-member Marine unit to provide help.
Barack Obama, the president, promised on Wednesday to mount an all-out rescue and humanitarian effort to help the people of Haiti overcome what he called a "cruel and incomprehensible tragedy".
As part of the relief effort one of the US navy's large amphibious ships, the USS Batann, has been ordered to Haiti with a marine expeditionary unit on board.
The ship is one of more than a half dozen, including frigates, a destroyer and a guided missile cruiser, being sent to the country.
General Douglas Fraser, the head of the US Southern Command based in Miami, said at a news conference that the Pentagon was "seriously looking at" sending thousands of marines to assist with disaster relief efforts and security in Haiti.
The troops would aim to keep the peace in the event of post-disaster unrest as part of a larger international effort overseen by the United Nations, whose peacekeeping operation headquarters was destroyed in the quake.
Pleas for assistance
Other countries have also been stepping up assistance efforts, with China announcing Thursday that the Red Cross Society of China has pledged to donate $1 million of emergency aid to Haiti.
China has also sent a team of 60 relief personnel to the country, including search and rescue crews, medics and seismological experts.
The team will bring rescue, communications and security equipment as well as 10 tonnes of food, medicine and other supplies.
Iceland, France and Spain have also dispatched search and rescue teams to the area, while commercial airlines have halted passenger services to Haiti, switching their aircraft to help with airlifting aid to the country.
Celebrities, musicians and athletes have also mobilised pleas for aid to help the recovery effort, with many posting messages online via Twitter and other sites.
Wyclef Jean, the Haitian-born musician, was among those calling for an urgent global response to help those affected by the disaster.
He arrived in Haiti on Wednesday, and his charity website, Yele,org, has been inundated with donations and has crashed under heavy internet traffic.
Meanwhile Lance Armstrong, a seven-time winner of the Tour de France cycling competition, has pledged $250,000 to the victims of the earthquake.
"This is really when the global community has to step up and recognise that we're very fortunate and sometimes we have to reach out," he said.