Singer Justin Bieber has admitted his relationship with his mother Pattie Mallette is "pretty non-existing" but they are trying to repair their bond.

"I was distant because I was ashamed. I never wanted my mom to be disappointed in me and I knew she was. We spent some time not talking, so it takes time to rebuild that trust," Bieber told billboard.com.

But the two are now working to rebuild their relationship.

"She's living in Hawaii now, so it's hard, but getting better. She's an amazing woman and I love her," he said.

While he has been estranged from his mother, he is very close to his father, Jeremy Bieber.

Though Justin concedes his father was "not in a place to raise a kid", the 21-year-old singer believes it's unfair to call Jeremy a "deadbeat dad".

"He was immature. He left for like a year when I was about four, went to British Columbia, came back on Father's Day. I remember my mom said, 'If you're going to be here, you have to be here'. There's a misconception that he's this deadbeat dad, but he has been in my life since. I was with him on weekends and Wednesdays," he said.