Bryan Cranston says Aaron Paul is "like a son" to him.

The 57-year-old actor - who has 20-year-old daughter Taylor with wife Robin Dearden - has remained close to his 'Breaking Bad' co-star and they are still in contact all the time, even though the show ended several months ago.

He said: "We're very close. He's my pal for life. He's just like a son to me. Not just that but he's a really fantastic actor, and I have to say that he's an even better person."

Bryan is currently portraying former US president Lyndon B. Johnson in Broadway production 'All the Way' and finds appearing on the New York stage "very powerful".

He told Rolling Stone magazine: "There's more immediate reward on this stage then there was on the 'Breaking Bad' set. You're in the moment. You can say something and then hear an audience gasp or just hear them feel a sentence. Or laugh. It's very powerful. With television and film, it's different. It's fun too but you have to wait a long time for that indulgence."

The 'Malcolm in the Middle' star is on the hunt for "challenging" roles now 'Breaking Bad' is over.

Asked what sort of roles he is looking for, he said: Interesting and challenging ones. The most important thing for me, which was the case with 'Breaking Bad', is the story and the writing."

However, he won't rule out reprising his role as cancer-stricken chemistry teacher-turned-drug lord Walter White in forthcoming 'Breaking Bad' spin-off 'Better Call Saul'.

He said: "I have no idea [if I'll appear]. Possibly? I'd be open to it for sure! It'd be fun to go back into the New Mexico desert and play with all my old friends."