American economist Jeffrey Sachs said on Friday he has been officially nominated to head the World Bank by at least one of the countries that has publicly supported him.

Sachs, speaking to AFP one week before the World Bank's deadline for nominations, declined to name his official backers.

"It's been confirmed to me that my name has been put officially into nomination by one or more of the governments that has publicly endorsed my candidacy," the world-renowned economist said in a phone interview.

Sachs, 57, is the director of The Earth Institute at Columbia University and a special adviser to UN Secretary General Ban Ki-moon on the Millennium Development Goals.

He has devoted his wide-ranging career to ending extreme poverty, and has worked for decades in poverty alleviation projects around the world.

That has helped him garner endorsements from Bhutan, East Timor, Haiti, Jordan, Kenya, Malaysia and Namibia.

The World Bank declined to comment on his claim, noting the Board had stipulated that a short list of up to three candidates would be released only after considering names submitted by the March 23 deadline.

In early March Sachs announced he wanted to succeed World Bank president Robert Zoellick, who is stepping down when his term ends in June.

"Unlike previous World Bank presidents, I don't come from Wall Street or US politics," he declared in announcing his candidacy on March 2.

"I am a practitioner of economic development, a scholar and a writer. My track record is to side with the poor and hungry, not with a corporate balance sheet or a government. Yet the solutions work for all -- the poor, companies, governments and the rest of us -- by creating a more prosperous, healthy and secure world."

Significantly, his maverick move has not been endorsed by the United States, which has yet to name a candidate of its own, though he has sent a letter to President Barack Obama on the subject.

That could be crucial to his candidacy: under a tacit agreement dating to the founding of the institution, the US has always chosen the World Bank head -- and it has always been an American -- while Europe names a European chief of the International Monetary Fund.

But emerging economies have loudly protested that status quo, demanding greater representation at the two Washington-based institutions.

In recent days, Sachs said, he has had "wonderful" conversations "with heads of states who have been calling me, to express their backing, to see how they can help.

"It's exciting. Now I hope it works," he said, chuckling.

Sachs sidestepped a question about whether he has support from the BRICS emerging powerhouses -- Brazil, Russia, India, China and South Africa, saying "in three regions a government that supports me" will mobilize support in the region.

Support on the home front came Friday, in the form of a letter that 27 Democrats in the House of Representatives wrote to Obama pressing for his nomination.

"I'm very, very moved and very honored," Sachs said. "These are members of Congress whom I respect enormously, really admire."

"It means a lot to me. And I think it will mean a lot to the president, also."

A group of Nobel laureates and intellectuals have also written a letter endorsing his candidacy.

"I'm really honored to have a lot of support from people themselves who are leaders in science or the fight against poverty through their political leadership," Sachs said.

"And I'm feeling that support in many, many parts of the world."

The World Bank has said it plans to fill the post by the start of its spring meetings with the International Monetary Fund on April 20.