Michael Shannon believes being a father is the most significant responsibility in his life.

The 42-year-old actor is father to daughters Marion and Sylvia, whom he has with his partner Kate Arrington, and has said that making sure he's fulfilling his job as a parent is the most important part of his life, and he often puts his family above his work.

He said: ''The responsibility that holds the most significance in my life is being a father. So, honestly, lots of those moments don't happen on set. They happen in those brief periods where I actually get to go home and take the kids to school, pick them up, cook them dinner and put them to bed.''

And the 'Nocturnal Animals' actor - who was nominated for the Best Supporting Actor award at the Oscars for his role in the psychological thriller - even says he often takes on smaller roles so that he can spend more time with his family, as he's worried taking a lead role will mean he's away for too long.

He added: ''I don't really mind [playing small roles]. The smaller the part, the quicker I get home to my kids. That's the way I look at it. I'm more nervous about taking the big job and being away for a long time.''

The 'Man of Steel' actor even admits he was ''relieved'' when HBO's drama series 'Boardwalk Empire', on which he played Nelson Van Alden, came to an end in 2014, as he felt the five years he spent working on the project was long enough.

He told 'Entertainment Tonight': ''I'm not going to lie, when 'Boardwalk' was over, I was kind of relieved. I was grateful for the opportunity, but spending five years on something - that was about as much as I would want to do.''