Fifty-three million people are at risk of extreme poverty due to the global downturn, the World Bank has warned.
Its president Robert Zoellick says the world's poorest countries are facing a "human catastrophe" that will continue to get worse unless more is done to tackle the financial crisis.
"There is widespread recognition that the world faces an unprecedented economic crisis, poor people could suffer the most and that we must continue to act in real time to prevent a human catastrophe," he said.
The World Bank, meeting this weekend for its spring summit, warns that investment capital has dried up in poorer countries, while exports have also reduced sharply and commodity prices have slowed the flow of cash sent home by nationals living abroad.
As a result the bank has announced a tripling in its investment in financial safety nets and other protections to $12 billion over the next two years.
"Services such as water and sanitation, energy, transport and telecommunications are vital in the fight against poverty," commented German finance minister Heidemarie Wieczorek-Zeul.
"For this reason our government has included infrastructure financing in developing countries in its second economic stimulus package."