Visiting British Prime Minister Gordon Brown warned on Wednesday against trade protectionism "that history tells us in the end protects no one."

In a formal address to a joint session of the US Congress, Brown said that any protectionist instincts on trade must be resisted, noting that such policies ultimately make every nation vulnerable.

He said that an "economic hurricane" has swept the world, creating a crisis of credit and a crisis of confidence.

"Our task is to rebuild prosperity and security in a wholly different economic world, where competition is no longer just local, but it's global, and where banks are no longer national, but they're international," he said.

"And we need to understand, therefore, what went wrong in this crisis, that the very financial instruments that were designed to diversify risk across the banking system instead spread contagion right across the globe," he told US lawmakers.

Brown further said that today's financial institutions are so interwoven that a bad bank anywhere is a threat to good banks everywhere.