Undefeated rising star Tim Tszyu of Australia has hit back at WBC, IBF, WBA junior middleweight champion Jermell Charlo.

Tszyu will return to the ring next month, when he faces domestic rival Michael Zerafa in Newcastle on July 7.

Charlo is back in the ring ten days later, on July 17, when collides with unbeaten WBO champion Brian Castano in a full division unification.

Some are calling Tszyu the future of the junior middleweight division - but Charlo disagreed in a recent interview.

“Tim ‘Kostya’ Tszyu is not on a level to even fight for a world title,” told Ringside with the Lions.

“He ain’t even on the level to fight some of the guys that I’ve knocked the f--- out of and he ain’t even going to get no chance to fight me, probably throughout my career. I’m just being honest with you.”

Tszyu is ranked as the top contender under the WBO.

And he's confident in his ability to land Charlo, because he intends to do whatever is necessary to force a mandatory fight when the time comes.

“Once I become mandatory one day, he won’t have no choice but to fight me. The American boys are like that, they like to run their mouths a bit. What we do here in Australia, we knock them out just the way my dad used to do. Knock them out and come back here. He knows who I am. He’s aware. It’s better than being the unknown," Tszyu said to Fox Sports.

“Domestically I have fought everyone here that’s possible. There’s one last name, one last key to the puzzle left. I feel like I’ve cleaned up my division completely, from the super welterweights to the middleweights It’s been good in a certain way, but after this there’s only one option.”