Russia's flagship state news channel is advertising a new programme hosted by Tucker Carlson, apparently without the firebrand rightwing US TV host's knowledge or consent.

Since last week, Rossiya 24 has run ads with a montage of Carlson repeatedly saying "Russia" and promising: "The high-profile American presenter is moving to another level. Here."

The ad then cuts to a screen showing a logo: "TUCKER ROSSIYA 24."

But Carlson told the Financial Times that he was unaware of the planned show, which Rossiya advertised on Friday as debuting "at the weekend", according to BBC Monitoring.

"I have no idea what you're talking about. I've never heard of this, or the channel. Of course I'm not hosting a show on Russian television. That's absurd. Please," Carlson said in a text message.

"I've never seen this. I have no clue what it's about. More Russia-related bullshit. There's so much I can't keep up," he added.