European leaders on Wednesday united behind calls for a “Bretton Woods II” summit to redesign the world’s financial architecture. Britain argued that the meeting could also be used to seal a long sought global trade deal.

Gordon Brown, Britain’s prime minister, said the world should turn the financial crisis into an opportunity and reform global institutions, such as the International Monetary Fund, conceived in 1944 when western leaders met in Bretton Woods, New Hampshire, and mapped out a postwar financial order.