Artists need to “keep the flag of truth flying” after Donald Trump’s election victory, the legendary Scottish actor Brian Cox has said.

Cox, who played Logan Roy in the hit HBO series Succession, also said the world has “never been in a more dangerous place than it is at the moment” as he reflected on the US election campaign and a second impending Trump presidency.

“As artists we have to bang the drum, we have to keep going,” he said in an interview with the Guardian. “We mustn’t put up with it. That’s why I admire people like Mark Ruffalo [a longtime advocate for social justice].

“I’m not going to give up on my criticism of Trump. I think it behoves artists to not give up, to keep the flag of truth flying, because it’s been so abused in recent years.”

Cox went viral on Tuesday night after making his disdain for Trump known during a virtual appearance on Channel 4 alongside the former UK prime minister Boris Johnson.

The 78-year-old, who splits his time between London and New York, said he was “acutely depressed” about the election and felt like he just had to “ride it out”.

Cox said: “There’s probably nobody more surprised than Trump himself. I think he was expecting to talk about voter fraud. But the American people have bought into him, which I find absolutely astonishing.

“It’s extraordinary that he has so many Catholic voters. I’m not religious at all, but I was born a Catholic. So I know about the Catholic doctrine and Trump’s sins are unbelievable. How can they possibly rationalise their faith in relationship to him?”

He added: “I’ve got two sons in America, I worry about what’s in store for them. The only person Trump cares about is himself. It’s hard to predict what he’ll be like.”

Trump received the 270 electoral college votes needed after capturing three battleground states from the Democrats – Georgia, Pennsylvania and Wisconsin. He picked up a small but significant share of Black and Hispanic voters, and made narrow gains with men and women. He also succeeded in locking down his traditionally older, white base of voters, and slightly expanded his margins with other groups.

“I look at the US and think it’s a fucking mess,” Cox said. “It doesn’t know who or where it is. Trump’s vitriol towards Harris during the campaign was unbelievable.

“I wasn’t the biggest fan of Harris, but I think she did incredibly well in the short time she had. She didn’t have a chance, the poor woman, and I blame Biden for that. He was clearly out of it, everybody in the world saw it, and he wouldn’t let go. A kind of hubris kicked in. And his hubris has been partly responsible for what’s happened.”

The stage and screen actor, who has numerous accolades under his belt including two Laurence Olivier awards, an Emmy and a Golden Globe, said the Democrats were also hamstrung by the war in the Middle East.

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Cox said: “Biden was in his last term, he could have done a lot more about that. What’s happening in Gaza is a genocide, there’s no question about it. It’s horrific. But it’s not going to get any better under Trump, because he’s a great friend of Netanyahu, so who’s going to be saying ‘stop it’ now, ‘behave yourself’?”

He added: “I think the world has never been in a more dangerous place than it is at the moment.”

Cox also spoke about other crises he believed Americans would be facing, including reproductive rights and the climate crisis.

“Women are being treated as second-class citizens in America and it has to stop, it’s gone on for far too long,” he said. “Nobody should be discussing what a woman should do with her body, only they should advocate for what happens to their body. How dare we make that assumption? It’s so retrograde.”

He added: “I can’t believe I’m living in the 21st century, because we don’t seem to progress as human beings. We seem to make the same mistake time and time again.

“The world’s in deep shit like never before. Trump’s not going to do anything about the climate crisis because he doesn’t believe it, no matter the evidence.

Cox was also insistent that he would “never play Trump”. He said: “I couldn’t play him for all the tea in China, there’s no virtue in him.”