The chief of the International Monetary Fund says it is on the verge of sharply increasing the size of the fund it has to lend to economically troubled nations around the world.

As global finance ministers gather in Washington for springtime IMF and World Bank meetings, the International Monetary Fund says it already has collected $320 billion in new pledges from developed nations in the past few months. None of it is from the United States, which in the past has been the IMF's chief supporter, but says with its own budget difficulties it has no plans to contribute more now.

IMF managing director Christine Lagarde says she expects more pledges from the IMF's 188 member countries in the coming days.

“As part of the outcome of this meeting, we expect our firepower to be significantly increased.”

Lagarde said the world economy is recovering from the threats posed by the European debt crisis, now that Greece has secured a new international bailout and Europe has increased the size of its rescue fund to handle future emergencies. But she also voiced concern about new threats to the global economy.

“If I was to use a weather analogy, because we are all very fond of weather reports, we are seeing light recovery, and blowing in a spring wind. But we are also seeing some very dark clouds on the horizon, which is another way to tell you there is a bit of a recovery, timid and a fragile situation with still high risks.”

She said the risks include high unemployment throughout the world, renewed economic stresses in Europe for other debt-ridden countries and protracted slow economic growth.

The 17-nation European bloc that uses the eurozone has pledged $200 billion of the new funds, with Japan saying it will contribute $60 billion. Switzerland, Norway, Sweden, Poland and Denmark have also said they would loan the International Monetary Fund more money to support the global lending efforts.