Robert Downey Jr calls Mel Gibson a `stand-up guy`

Downey Jr appeared uncomfortable on US TV when he was asked first about Gibson and then Charlie Sheen.

While he refused to discuss Sheen's problems he seemed keen to defend Gibson, who cast him in The Singing Detective, his first film after jail.

'The truth is he and I have a friendship that spans well over two decades,' the actor said, taking off light-colored glasses he was wearing on the Today Show as the talk turned serious.

'He's a stand-up guy - he always has been for me.

'When I was not hireable he put his ass on the line. I couldn't get insured and he said, 'I'll take that chance'.'

Asked what he thinks of Gibson's own issues that he is battling, Downey Jr insisted the reality may be very different than what the world was presented with.

'The reality of what happens to people and the mistakes they make and the journey they are on - and then there's the media and everyone else's opinion.

'And so the way I honour my friendship with him is by not getting too involved in whatever the public discussion is. Because it usually has very little to do with much besides people's own egos and interpretations.'