International Monetary Fund (IMF) chief Christine Lagarde said on Wednesday that the Fund has received commitments of additional resources up to about 320 billion U.S. dollars.

"I have been informed today by the Swiss authorities of their intention to provide a substantial amount of additional financing commitments to the IMF," Lagarde said in a statement.

"I also received today firm indications of support from several other countries which, together with Switzerland's contribution, will amount to over 26 billion dollars. These countries will formalize their individual commitments in the coming days," she added.

"This brings to about 320 billion dollars the commitments received so far," she noted.

The financial pledges from Switzerland and other countries are in addition to previous pledges for increased contributions from the euro area, Japan, Sweden, Norway, Poland and Denmark.

Lagarde said Wednesday night at an event of Bertelsmann Foundation that the world economic outlook is "slightly improved", yet still fragile and "extremely unstable."

"The IMF is about stability," but there is "big shortfall of stability at the moment," she added.

Boosting the IMF's resources is likely to dominate discussions on the Spring Meetings of the IMF and the World Bank, which will officially start on April 20 in Washington.