The United States picked a public health expert of South Korean origin as its candidate for the World Bank presidency, a job emerging market economies are contesting for the first time, Reuters reported.

In an announcement on Friday, March 23 at the White House President Barack Obama said he was nominating Jim Yong Kim, president of Dartmouth College in New Hampshire and former director of the Department of HIV/AIDS at the World Health Organization.

Angola, Nigeria and South Africa have endorsed the nomination of Nigerian Finance Minister Ngozi Okonjo-Iweala, a respected economist and diplomat, as a candidate to take over the bank when Robert Zoellick steps down in June.

Meanwhile, a spokeswoman for U.S. economist Jeffrey Sachs said he was withdrawing his nomination in support of Kim.

"Professor Sachs supports Dr Kim 100 percent and with complete enthusiasm," spokeswoman Erin Trowbridge said.

The United States has held the presidency since the bank's inception after World War Two, and a European has always headed the IMF.

The rise of emerging economies such as China, India and Brazil has put pressure on the United States and Europe to throw open the selection process for both the bank and the IMF.

Last year, all of the bank's 187 member countries agreed on a transparent, merit-based process to select a president.