Barack Obama told Britain's Prince Harry, in an interview recorded in Toronto earlier this year and aired in the U.K. today, that people in government should be careful while using social media, although he didn't mention U.S. President Donald Trump directly.

"All of us in leadership have to find ways in which we can recreate a common space on the internet," the former president said to Harry, who was guest host for BBC Radio 4's Today program.

The show was recorded when Obama and Harry met up at the Invictus Games in Toronto in September. Both men said the interview was Obama's first since leaving the presidency in January.

Obama said the way people communicate via social media risks splintering society and leaders have to ensure the internet does not divide users with differing points of view. 

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Obama and Harry met up during the Invictus Games in Toronto on Sept. 29. (Chris Jackson/Invictus Games Foundation/Getty Images)

"One of the dangers of the internet is that people can have entirely different realities, they can be just cocooned in information that reinforces their current biases."

Obama said moving online communities offline helped people see that many issues were not as simple as they might seem in a social media feed.

"It's also, by the way, harder to be as obnoxious and cruel in person as people can be anonymously on the internet," he said.

'I miss the work'

He told the prince he felt "a sense of serenity" the day he left the White House, despite feeling much important work remained unfinished.

Obama said it has been "hugely liberating" to be able to set his own agenda in the morning and have the time to talk with his wife, Michelle Obama, since leaving the White House.

"I miss the work itself because it was fascinating," Obama said of his eight years in the Oval Office, citing his health-care reforms as one of his proudest achievements.

But getting off what Harry called the "political treadmill" means he now he has the time to think and reflect, and there's a "lower intensity level" — though that means "you don't have the same adrenalin rush."

"My life had been so accelerated; everything felt like, and still feels to some extent, like it's moving in slow motion — not in a bad way."

Harry asked about a subject they have both expressed an interest in: "how to give youth a voice, because they have great ideas and they are inevitably the ones who are going to inherit the mess that we leave behind."

Obama said he is "obsessed" with helping to train the next generation of leaders.

"How do I transmit whatever knowledge or experience that I've gained to others to help them become more effective and more powerful?"

Harry asked Obama a "lightning round" of questions of the type normally put to entertainers, not politicians.

The former president declined to say whether he wears boxers or briefs, but was willing to say he prefers Aretha Franklin to Tina Turner — "Aretha is the best," he said of the Queen of Soul — and favours retired basketball star Michael Jordan over current star LeBron James.

In a brief live segment at the end of the show, Harry said he did not know if Obama would be on the guest list for his wedding in May to American actress Meghan Markle as it had not yet been drawn up.

But he did say his fiancée had enjoyed her first Christmas as a guest of his grandmother, Queen Elizabeth, at her country estate.

"She really enjoyed it, and the family loved having her there," said Harry.

With files from The Associated Press, Reuters