Prince George meets the Obamas in his PJs

Prince George stayed up past his bedtime to greet the president of the US President Barack Obama.

Britain's Prince George meets with US President Barack Obama, centre and first lady Michelle Obama, at Kensington Palace, London, Friday April 22, 2016. Source: AAP

US President Barack Obama and his wife Michelle Obama have met with two-year-old Prince George during their UK visit for the Queen's 90th birthday. 

Dressed in his flannelette pyjamas, slippers, and nightgown, the young prince shook hands with Mr Obama.

Prince George was also photographed riding the wooden rocking horse the Obamas presented him at his birth.

Kensington Palace published photographs of the meeting online, with the young Royal's bedtime outfit attracting commentary.

A bathrobe identical to that worn by the prince, designed by My 1st Years and costing £25 (approx A$15) has already sold out. 

The visit took place before the Obama's formal dinner engagement with the Duke and Duchess of Cambridge as well as Prince Harry at Kensington Palace.