Barack Obama says ‘we’re living in strange and uncertain times’ and takes dig at Trump during speech marking Nelson Mandela's 100th birthday

Barack Obama has said the world is living through “strange and uncertain” times, as he decried the type of “strongman politics” practised by Donald Trump in his most high-profile speech since leaving the White House.

Mr Obama urged people around the world to respect human rights and other values now under threat, in an impassioned address as he marked Nelson Mandela’s life on the 100th anniversary of his birth.

The US’s first black president was greeted by a stadium full of people in Johannesburg, South Africa, with chants of “Yes, we can” – his well-known campaign slogan from 2008.

“Each day’s news cycle is bringing more headspinning and disturbing headlines,” Mr Obama said, in an apparent reference to Mr Trump who he did not mention by name during the speech. These days “we see much of the world threatening to return to a more dangerous, more brutal way of doing business”, he added.

He attacked “strongman politics”, saying that “those in power seek to undermine every institution ... that gives democracy meaning”.

Mr Obama hit out at the current increase in attacks on free press, adding that there is an “utter loss of shame among political leaders when they’re caught in a lie”. It is not much of a stretch to suggest that Mr Obama was again thinking of his successor Mr Trump – who has repeatedly admonished “fake news”, even when they are pointing out false statements he has made.

He noted that though the world had progressed leaps and bounds – in terms of ending apartheid, the fall of dictatorships, and technology connecting people – there is a “politics of fear, resentment, retrenchment... now on the move ...[at a] pace that seemed unimaginable even a few years ago”.

Mr Obama appeared relaxed, joking with new South African president Cyril Ramaphosa who had taken the podium earlier to a standing ovation and singing from the crowd in support of his recent electoral victory.

The US leader said Mr Ramaphosa “brings new hope to this great nation”, but the crux of his lecture was to focus “on where we’ve been and how we arrived, in the hopes that it offers a roadmap on where we need to go next” in passing the torch of Mr Mandela’s ideals.

“Madiba,” as he was affectionately referred to by all the day’s speakers, was released from his decades in prison just “a few months after the fall of the Berlin Wall”, Mr Obama reminded the crowd.

“On Madiba’s 100th birthday we stand at a crossroads... a moment in time in which two very different visions” can take hold, Mr Obama said.

Those who believe in reducing income inequality, fight climate change, believe in education for all “have a better story to tell”, Mr Obama said.

However, he warned: “To say our vision of future is better is not to say that it will inevitably win.”

He explained how the wealthy have an outsized influence on politics, particularly in “populist movements... cynically funded by right-wing billionaires”, in what may have been a jab at Mr Trump and major Republican donors like the Koch brothers.

He said “those in power seek to undermine every institution ... that gives democracy meaning” and attacked “strongman politics”.

“I am not being alarmist, I am simply stating the facts. Look around,” the former US leader added.

He dipped momentarily into a rhetoric of idealism and a fierce defence of tolerance.

In a sobering moment, Mr Obama noted “the struggle for basic justice is never truly finished”.

“History shows the power of fear. History shows how easily people can be convinced to turn on those who look different... We’re going to have learn from the mistakes of the recent past,” Mr Obama said. He also pointed to a world history of xenophobic nations being “consumed by civil war”.

However, Mr Obama sought to strike a note of hope by saying that the world had made it “through darker times. We’ve been through lower valleys”.