Obama urges young to reject isolationism after Brexit plea

US President Barack Obama on Saturday implored young people in Britain to reject isolationism and xenophobia, a day after wading into the Brexit debate over the country's referendum on membership of the European Union.

Obama -- on the last day of a three-day visit, likely to be his last to Britain before leaving office in January -- earlier marked the 400th anniversary of English playwright William Shakespeare's death with an early morning trip to London's Globe theatre to see scenes from "Hamlet" being performed.

The president later played golf with British Prime Minister David Cameron at a luxury golf course north of London.

Speaking to an audience of 500 young Britons in the capital, Obama said people should take a more "optimistic view".

"We see new calls for isolationism, for xenophobia. We see those who had called for rolling back the rights of people. People hunkering down in their own point of views and unwilling to engage in a democratic debate," the president said.

"And those impulses, I think we can understand: they are reactions to changing times and uncertainty.

"But when I speak to young people, I implore them -- and I implore you -- to reject those calls to pull back.

"I am here to ask you to reject the notion that we are gripped by forces that we can't control. And I want you to take a longer and more optimistic view of history."

Touching on the threat from the Islamic State group, Obama also said the greatest allies in the anti-terror fight were Muslim Americans.

"If we engage in Islamophobia we are not only betraying what is essential to us, but, just as a practical matter, we are engaging in self-defeating behaviour if we are serious about terrorism," he said.

- 'Optimistic view' -

On Friday, the president warned Britain against leaving the EU, undercutting a key argument of Brexit campaigners by saying London would be "at the back of the queue" for a post-Brexit trade deal.

Eurosceptics reacted with irritation with London mayor Boris Johnson describing it as "downright hypocritical" for Obama to intervene as the United States would not accept the same limits on its own sovereignty as EU members do.

Nigel Farage, leader of the UK Independence Party, meanwhile, dismissed Obama's warning on trade, saying a deal was in both countries' interests.

Asked in Saturday what he thought his biggest achievement was in office, Obama cited bringing in health insurance and dealing with the financial crisis.

"Saving the world economy from a great depression, that was pretty good. I'll look at the scorecard at the end. I think I have been true to myself," he added.

Obama also had a meeting with British opposition Labour leader Jeremy Corbyn.

"The two leaders discussed the impact of globalisation on labour and working people, and the need to take steps to reduce inequality around the world. They agreed that the UK should remain a member of the EU," a White House source said.

Corbyn said the talks were "excellent".

They discussed "the challenges facing post-industrial societies and the power of global corporations and the increasing use of technology around the world and the effect that has," the veteran socialist said.