The fashion range designed by model Kate Moss for Topshop has generated around £3m in sales in its first week.
That figure was ahead of the chain's forecasts by "quite a long way", a spokeswoman said.
The model's fashion range launched in New York upmarket department store Barneys last week, and in Stockholm earlier this week.
The British retailing group plans to launch three stores in Manhattan following the success of Moss's collection, owner Philip Green confirmed earlier this week.
'We are looking for sites this week (in the States) but realistically nine months is the time horizon to get a store sorted and opened,' Green said.
Green, one of Britain's most successful retailers, added he was also scouting for property in Paris, with the aim of opening a Topshop flagship store there in the next few months.
Moss was paid a reported £3 million to design the 50 item range for Top Shop.
Topshop's launch in the United States is a bold move with rivals like Marks & Spencer having failed to break into the world's most competitive retail market in the past.
