Obama urges young voters to 'reject cynicism and xenophobia'

President Barack Obama has left the UK after a flying visit in which he warned Britons not to vote to leave the EU.

The US leader waved to waiting crowds as he climbed aboard his person US Air Force One jet today.

He is now headed to Germany where he will hold talks with chancellor Angela Merkel, one of his closest allies in Europe.

Barack Obama has said he hopes his pro-EU stance will help persuade British voters in the upcoming referendum - as he warned a US-UK trade deal could take up to a decade to negotiate.

Speaking to the BBC at the end of his trip to London, the US President said he expected to conclude a trade deal with the European Union before leaving office in the autumn - though said it may not be ratified during that time.

But if the UK votes to leave the EU, he added, it could take between five and 10 years to reach the same point.

The US leader has made a number of statements during his visit, voicing his view that Britain would be better off remaining a member of the EU.

"My hope is, is that this is something that would have some influence on how voters think," he said.

"For ordinary voters I thought it would be relevant to hear what the president of the United States, who loves the British people and cares deeply about this relationship, has to say about it."

U.S. President Barack Obama has found time during his official whirlwind visit to the UK to take time out for a spot of golf with Prime Minister David Cameron.

The two politicians played a round of golf at The Grove, just north of London today, after Obama met with Labour Party leader Jeremy Corbyn to discuss "the challenges facing post-industrial societies and the power of global corporation".

Labour leader Jeremy Corbyn said he had an "excellent" discussion with US President Barack Obama.

In the private meeting, held on the second day of Mr Obama's UK visit, the president also congratulated him on being elected leader of the opposition in September, Mr Corbyn said, adding that he had "enjoyed" the meeting.

Asked what they discussed, he said:

They also spoke about inequality and poverty levels, he said, and "very briefly" touched on the subject of Britain's membership of the EU.

President Barack Obama has urged young people to reject calls for isolationism or xenophobia at a special meeting with young people.

The US leader will be also taking questions from the crowd in Westminster.