Breaking Bad star Bryan Cranston has described the finale of the show as a "roller coaster ride".

The Emmy Award winner also told Radio Times that the AMC drama's final eight episodes are exactly what he had hoped for.

"The ending of Breaking Bad is very unapologetic and appropriate and exciting," said the actor, who plays former chemistry teacher turned drug lord Walter White. "It's a roller coaster ride."

Cranston also predicted that the audience's remaining sympathy for Walt will continue to waver as the series finale and his "downfall" approaches.

"The thing that affects people when they're watching a tragedy - whether it's Shakespeare or contemporary - is that the potential of the human being, the potential of a person, was there and it didn't work out," he explained.

"If we're introduced to a character that's despicable and they continue their despicable nature, we don't sense that as a tragedy because we hated them from the beginning. They're just the villains."

Breaking Bad's final season continues on Sunday nights on AMC in the US, and is available this side of the Atlantic on Netflix the following day.