U.S. urges allies against joining China-backed AIIB

Related story: Why Europe dismisses U.S. concerns and to join AIIB

The euro zone's biggest economies -- Italy, France and Germany -- have Britain in dismissing U.S. concerns and will become founding members of the Asian Infrastructure Investment Bank (AIIB).

Experts say the development is a diplomatic and financial success for China, which is behind the new financial institution, and shows how Europe is prepared to look east for trade deals.