Leaders of the three West African nations hardest hit by Ebola sought support from the international financial community amid warnings that the widening epidemic is devastating the region’s fragile economies.

The presidents of Liberia, Sierra Leone and Guinea discussed strategies to combat the deadly virus during a meeting in Washington of the World Bank and the International Monetary Fund.

The World Bank, which provides loans and funding to developing nations, has pledged $400 million to help combat the epidemic in West Africa, where the disease has claimed more than 3,400 lives since the outbreak began earlier this year.

Already, the three hardest-hit nations have seen significant impacts on their gross domestic product, according to a report the bank released this week, as rural families have abandoned farms and urban centers have closed schools and businesses.

The report says that if the virus stops spreading, financial losses from declining agricultural output and business revenues could reach roughly $3 billion.