Pope Francis at his general audience at the Vatican on November 16. Alessandro Bianchi/Reuters As US President Donald Trump was being sworn into office, Pope Francis warned about the rise of populist leaders such as Hitler.

The pontiff made the comments to the Spanish newspaper El Pais, warning that Trump-like leaders abuse citizens' judgement in times of crisis.

"When I started to hear about populism in Europe I didn't know what to make of it, I got lost, until I realised that it had different meanings," the pope said. "Crises provoke fear, alarm.

"In my opinion, the most obvious example of European populism is Germany in 1933. After [Paul von] Hindenburg, after the crisis of 1930, Germany is broken, it needs to get up, to find its identity, a leader, someone capable of restoring its character, and there is a young man named Adolf Hitler who says: 'I can, I can.'

"And all Germans vote for Hitler. Hitler didn't steal the power, his people voted for him, and then he destroyed his people.

"That is the risk. In times of crisis, we lack judgement."

The pope added it was natural for people to want to regain their identity when it is challenged — calling for closed borders as a result — but said it was as important as ever to maintain open dialogue with one's neighbours.

Earlier last year, the pope questioned Trump's Christianity because of his stance on borders and immigration.

Despite the strongly worded warning, the pope insisted that the world must "wait and see" before judging Trump and see how he performs in his role.

He said: "I don't like to get ahead of myself nor judge people prematurely.

"We will see how he [Trump] acts, what he does, and then I will have an opinion. But being afraid or rejoicing beforehand because of something that might happen is, in my view, quite unwise.

"It would be like prophets predicting calamities or windfalls that will not be either."

The pope also warned that he felt people were more "anesthetised" than ever, describing people's apathy to reality as "the most dangerous illness."