More than three dozen nations and organizations have pledged more than 5 billion U.S. dollars so far on Wednesday to assist Haiti following the recent devastating earthquake, just hours after UN Secretary-General Ban Ki-moon opened a day-long international donors conference by calling for the wholesale rebuilding of the country.

U.S. Secretary of State Hillary Clinton, co-host of the high- level conference, said the United States would pledge 1.15 billion U.S. dollars over the next two years for Haiti's long-term recovery and reconstruction.

"This money will go to supporting the government of Haiti's plan to strengthen agriculture, energy, health, security and governance," she told the conference, adding that all financial donations must be made in a smarter way that produces real results for Haitians.

At least 3.8 billion in pledges is being sought as a first installment in 11.5 billion dollars needed over 10 years for Haiti's post-quake reconstruction.

The conference, co-chaired by Brazil, Canada, the European Union, France and Spain, brought together representatives from more than 130 countries.

Brazil pledged 172 million dollars and Catherine Ashton, the European Union foreign affairs chief, announced the EU's pledge of roughly 1.6 billion dollars.

Montenegro pledged 10,000 dollars, with Georgia and Estonia each promising to donate 100,000 dollars.

In his opening address on Wednesday morning to the conference at the UN Headquarters in New York, Ban appealed to donors to provide 11.5 billion dollars over the next 10 years for the reconstruction of the Caribbean nation.

"What we envision, today, is wholesale national renewal ... a sweeping exercise in national-building on a scale and scope not seen in generations," he told delegates from more than 130 nations attending the high-level meeting aimed at securing the financial resources necessary to help Haiti recover and rebuild after the Jan. 12 quake.

Some 3.9 billion dollars of the 11.5 billion dollars being sought will be channeled into specific projects through a newly- created Interim Haiti Recovery Commission during the next 18 months.

Ban said reconstruction work must move in tandem with emergency relief and urged donors to provide further support to the revised humanitarian appeal for Haiti. That appeal is calling for 1.4 billion dollars, but is currently only 50 percent funded.

"The rainy season is fast approaching. Some camps for displaced persons are at risk of flooding. Heath and sanitation issues are growing more serious," Ban said.

Haitian President Rene Preval, U.S. Secretary of State Hillary Clinton, and UN Special Envoy for Haiti Bill Clinton, also the former U.S. president, are also co-hosting the conference, entitled "Towards a New Future in Haiti."

They noted the courage and solidarity shown by the Haitians in the midst of the unprecedented suffering resulting from the quake and the outpouring of generosity and support from the country's international partners. At the same time, they underscored that Haiti's road to recovery will be a long one and one which will require continued global support.

The conference is co-chaired by Brazil, Canada, the European Union, France, and Spain as leading donors to Haiti, which was already the poorest nation in the Western Hemisphere before the disaster.

The Jan. 12 quake struck close to the capital, Port-au-Prince, and resulted in the deaths of more than 200,000 people. It also left one third of the country's 9 million people in need of aid.

The total value of damage and losses sustained has been calculated at approximately 7 billion dollars, according to the UN Development Program (UNDP).

Its Administrator, Helen Clark, voiced hope that the conference "will pave the way for building back better in Haiti. With sufficient resources, the vision presented today by the Government of Haiti on behalf of Haitian people can become reality."

She also emphasized the need for Haitian ownership of the recovery process, with international assistance being aligned with the country's priorities.

"With the necessary resources, we can assist the Government to develop effective social protection to combat extreme poverty; we can help improve access to education, health services, and clean water and sanitation; and we can help promote food security and nutrition," Clark said.

Haitian Prime Minister Jean-Max Bellerive presented the country's needs and its plans for recovery. Countries, international organizations, and other partners at the meeting will be able to pledge resources, to coordinate in support of Haiti's long-term recovery and to commit to a sustained effort to support the country.

UN General Assembly President Ali Treki urged participants at the donors conference to further support reconstruction efforts, and hoped that the pledges made by the international community "would be commensurate with the needs of the people and Government of Haiti and firmly pave the way to a brighter future," his spokesperson stated.