The meetings open after Wall Street's worst weekly rout on record, and as governments around the world struggle to contain the most severe financial meltdown since the 1930s Great Depression.

Finance leaders from the twin institutions' 185 member nations and private financiers gathered in Washington in search of an effective response to the crisis that has slowed the advanced economies to a standstill.

Late on Friday, the finance chiefs of the Group of Seven richest industrialized countries agreed to use 'all available tools' to support major banks and prevent their failure as they sought to dampen a financial firestorm threatening more mayhem.

Their broad five-point action plan followed another day of massive falls on the markets as investors rushed to the exits, putting G7 officials under intense pressure to come up with a convincing accord.

US President George W. Bush, speaking early on Saturday after hosting G7 crisis talks attended by the IMF and World Bank leaders, said that all agreed the world financial meltdown required 'a serious global response'.

Mr Bush was joined by the G7 finance ministers from Britain, Canada, France, Germany, Italy, Japan, as well as International Monetary Fund chief Dominique Strauss-Kahn and World Bank President Robert Zoellick and other officials.

The central bank chiefs and finance ministers of the Group of 20, a grouping that includes rich and emerging nations, are to hold a crisis meeting on Saturday in Washington.

US Treasury Secretary Henry Paulson said late on Friday he expects emerging nations in the G20 to sign up to the G7 five-point action plan.

'I would be surprised ... if they didn't look at the action plans and didn't endorse them,' Mr Paulson told reporters.

'Never have all of us been so dependent on the other and so interdependent.

We need to work together.' -- AFP