Star Wars stormtroopers dance with the Obamas

In video released by the White House, President Barack Obama and First Lady Michelle Obama held a dance-off with R2-D2 and some stormtroopers to celebrate so-called "Star Wars Day".

Fans celebrate the hugely successful film series on the fourth day of the fifth month thanks to a pun on the Jedi salutation, "May the force (fourth) be with you".