David Harewood has criticised the lack of opportunities for young black actors in the UK and has advised them to consider heading to the US.
The star - who was recently awarded an MBE - said there was a lack of "authoritative, strong black characters" for British actors.
Birmingham-born Harewood blamed the British TV industry for its lack of risk-taking and said it was less "ambitious" than its US counterpart.
Harewood, 46, made his comments at the launch of Homeland, a new US drama series in which he stars that is shortly to be screened by Channel 4.
Harewood plays the director of a CIA counter-terrorism team in the Golden Globe-winning thriller, also starring fellow Brit Damian Lewis, as well as Claire Danes and Mandy Patinkin.
He said: "Unfortunately there really aren't that many roles for authoritative, strong, black characters in this country. We just don't write those characters, that's a fact."
Harewood said British actor Idris Elba - who found fame in Baltimore-based The Wire - had talked to him about the greater opportunities offered across the Atlantic.
He said: "I can remember talking to Idris years ago about these frustrations and he told me 'I'm going to America', and I kind of thought, 'What are you doing that for?'.
"Look at him now. He's a huge star; he made the right decision, even though it took him a long time to crack the US.
"I knew what I needed to do. I simply wouldn't have been given a role of that strength and authority in the UK."
Harewood has received acclaim for his portrayal of Nelson Mandela in BBC drama Mrs Mandela and the late Martin Luther King in London play The Mountaintop.
"Nelson Mandela and Martin Luther King are great roles, but they are very few and far between for us," he said.
"I don't want to trash this place, but I do think there is a certain lack of ambition in terms of telling a global story," he said.
"It's quite parochial sometimes. I don't think it's as ambitious. When you're sitting down watching the best of American TV, it is risk-taking."
He advised aspiring black British thespians to try their craft in the US.
"I would encourage, particularly young, black actors, to get to America or to at least try and have that ambition in your back pocket.
"They do seem to embrace a more diverse palette, and I think that's sad but that's just a fact. So I would encourage people to get there as quickly as they can."