One Direction's debut single has sold over one million copies in the US.

The British boy band - made up of Harry Styles, Niall Horan, Louis Tomlinson, Liam Payne and Zayn Malik - have become huge stars in the States and their first song, 'What Makes You Beautiful' has achieved an impressive 1,129,852 sales since being released four weeks ago.

Last month, the group - who were formed on the 2010 series of the UK version of 'The X Factor' after each member auditioned as a solo artist - made history when their debut album 'Up All Night' entered the US Billboard 200 chart at No.1, making them the first British group ever to debut at the top of the US charts with their first LP.

And last week it was announced One Direction were to headline Madison Square Garden in New York.

Niall said: ''To be headlining our own show in a venue that has played host to countless legendary acts that we have grown up listening to and adore is obviously a dream come true for us all.''

The 'One Thing' hitmakers were also honoured to be invited to the White House by US first lady Michelle Obama for Easter weekend, after an appearance at the Nickelodeon Kids' Choice Awards in Los Angeles in March, but politely had to decline the offer as they will be in Australia.