The couple confirmed reports last month that they had separated after three years of marriage, reported Contactmusic.
"You know, when you have two people who are incredibly busy and who are both very visible in the world, I think it can be challenging to keep that, that schedule and that kind of life in the same track, you know," he said.
But the 36-year-old actor insisted that he and Kerr, 30, would always remain in each other's lives for their young son Flynn.
"It's very challenging... I love Miranda and she loves me. We both adore and love our son. We both recognise and realise that we're going to be in each other's lives for the rest of our lives, raising our son.