By Daniel Hunter
The International Monetary Fund (IMF) would be "delighted" to co-operate with the China-led Asian Infrastructure Investment Bank (AIIB), according to its head Christine Lagarde.
Ms Lagarde said there would be "massive" room for co-operation between the two banks.
AIIB now has 30 members, including the UK, which was the first western nation to apply for founding membership.
The decision prompted criticism from the US, who believe the China-led AIIB could rival the World Bank which will be used by the Chinese government to grow its influence.
But the head of the IMF said she thinks the World Bank will co-operate with the AIIB as well.