Washington's baby panda Bei Bei makes his debut

A four-month-old panda cub, Bei Bei, has been introduced to the media at the Smithsonian National Zoo.

The cub, whose twin brother did not survive, was just 4oz (113g) at birth.

He now weighs 17.5lb (8kg).

He and his two-year-old sister Bao Bao belong to China, and will go there when they turn four years old to join the breeding programme there.