A New York exhibition exploring Chinese influence on Western fashion has become a summer smash-hit, attracting a record 670,000 visitors in a sign of China's growing clout in America.

Spread across 16 galleries, "China: Through the Looking Glass," is the most visited show at the Metropolitan Museum of Art's Costume Institute and has been extended for three weeks.

It broke the previous record set by a 2011 show celebrating the late British designer Alexander McQueen, which went on display shortly after his tragic death, the museum said.