US President Barack Obama speaks to college-bound students at a "Reach Higher" initiative event hosted by the first lady at the White House in Washington July 23, 2015. [Photo/Agencies]

LONDON -- US President Barack Obama has urged Britain to stay in the European Union (EU), saying that having Britain in the bloc "gives us much greater confidence about the strength of the transatlantic union," BBC reported Thursday.

The UK must stay in the European Union to continue to have influence on the world stage, Obama said in an interview with BBC.

"Having the UK in the European Union gives us much greater confidence about the strength of the transatlantic union," Obama told the British broadcaster ahead of his visit to Kenya.

The EU "made the world safer and more prosperous," Obama was quoted by BBC as saying.

In the interview, Obama lauded Britain as America's "best partner" for its willingness to project power beyond "immediate self-interests to make this a more orderly, safer world," according to BBC.

The US President also praised British Prime Minister David Cameron as an outstanding partner and congratulated the UK government for meeting the NATO's target of spending 2 percent of GDP on defense, BBC said.

British Prime Minister David Cameron has pledged to hold an "in or out" referendum on whether Britain should withdraw from the EU by 2017.