The Iranian director behind Oscar-nominated film The Salesman told about 10,000 protesters in London that solidarity against Donald Trump’s travel ban holds the power to “stand up to fascism, be victorious in the face of extremism”.

Speaking hours before the Oscars ceremony in Hollywood, Asghar Farhadi said the movement against the US president empowered people to “say no to oppressive political powers everywhere”.

He speaks to crowds in London

“I am extremely happy that the scattered reactions from people and art communities across the globe shown to the oppressive travel ban of immigrants has developed into a powerful and unified movement,” he told the protest on Sunday night.

“This solidarity is off to a great start. I hope this movement will continue and spread for it has within itself the power to stand up to fascism, be victorious in the face of extremism and say no to oppressive political powers everywhere.”

Appearing via videolink from Tehran, and joined by London mayor Sadiq Khanand Palme d’Or winner Mike Leigh, Farhadi said: “We are all citizens of the world and I will endeavour to protect and spread this unity.”

The London screening of The Salesman on Sunday evening wasintended to be a show of unity and strength against Trump’s travel ban, which attempted to block arrivals in the US from seven predominantly Muslim countries: Iran, Iraq, Libya, Sudan, Somalia, Syria and Yemen.