Joaquin Phoenix is ''still plagued by self-doubt''.

The 45-year-old actor has admitted he still finds himself ''petrified'' when he takes on new roles, and is always nervous that he won't be able to find ''the right kind of space'' to embody the character he has been given.

In a teaser for his upcoming interview on '60 Minutes' - which will air on Sunday (12.01.20) - interviewer Anderson Cooper notes in a voiceover: ''Phoenix is still plagued by self-doubt.''

And Joaquin then says: ''Yes, petrified. There are so many things that I want to express when I take on a role. I go through the script, I'm just like, full of ideas and so, I guess I'm just nervous that I'm not going to be able to find the right kind of space to express that.''

In a press release for the show's upcoming episode, '60 Minutes' says Joaquin will also discuss his childhood and the tragic death of his brother, the late actor River Phoenix, who passed away in 1993 at the age of 23 of combined drug intoxication.

The show will also feature the first group interview with the Phoenix family in decades.

Joaquin's self-doubt comes as he received critical acclaim for his portrayal of the titular DC Villain in the 2019 movie 'Joker', for which he won the Golden Globe for Best Performance by an Actor in a Motion Picture - Drama over the weekend.

And in his acceptance speech for the gong, he said he had been ''honoured'' to be shortlisted against fellow nominees Christian Bale ('Ford v Ferrari'), Antonio Banderas ('Pain and Glory'), Adam Driver ('Marriage Story'), and Jonathan Pryce ('The Two Popes').

He explained: ''I'm your f***ing student. I can't believe the beautiful mesmerising, unique work that you've all done this year, I know people say this but I really do feel honoured to be mentioned with you ...

''To my fellow nominees, we all know there's no f***ing competition between us.''