Video: Sumatran tiger cubs make first public at Smithsonian's National Zoo in Washington

Two cubs from highly endangered species had to pass swimming test before they could be allowed out in main enclosure

Two Sumatran tiger cubs, a male, Bandar and a female, Sukacita, make their public debut at the National Zoo in Washington, Monday 18 November 2013 (AP)

Two Sumatran tiger cubs have made their first ever public appearance at the Smithsonian's National Zoo in Washington, DC.

Visitors were treated to a first glimpse of the pair on Monday, when they were allowed out into the zoo's main tiger enclosure for just over an hour and a half.

The three-month-old cubs, named Sukacita and Bandar, played with their mother Dumai and seemed to pay little attention to the crowds drawn to watch.

Sumatran tigers are one of the most critically endangered species in the world, with only around 500 of the animals left both in captivity and the wild.