WASHINGTON — The World Bank on Sunday urged donor nations to speed up delivery of the money they've already pledged — and to give even more — to help poor countries weather the steep global recession.

WASHINGTON — The World Bank on Sunday urged donor nations to speed up delivery of the money they've already pledged — and to give even more — to help poor countries weather the steep global recession.

The bank said developing countries face especially serious consequences as the financial and economic crisis turns into what it described as a "human and development calamity."

In a communique, the World Bank's policy steering committee said the crisis has already driven more than 50 million people into extreme poverty, particularly women and children. "We must alleviate its impact on developing countries and facilitate their contribution to global recovery," the committee said.

World Bank chief Robert Zoellick said some of the poorest economies are being hit by "second and third waves" of the crisis.

"No one knows how long this crisis will last," Zoellick told reporters at the close of weekend meetings of the World Bank and the International Monetary Fund.

Both Zoellick and IMF managing director Dominique Strauss-Kahn expressed support for emerging democracies, such as China and Brazil, to have a stronger voice at the twin financial institutions.