Australian superstar Tim Tszyu is now closing in on a world title shot.

As reported on Tuesday, the World Boxing Organization issued an order which directs WBO, IBF, WBA, WBC junior middleweight champion Jermell Charlo to make a mandatory defense against Tszyu.

They have until June 20 to reach an agreement, or the fight will head to a purse bid.

Tszyu was ringside last month, to watch Charlo score a knockout over Brian Castano to become the undisputed champion at 154-pounds.

No Limit Boxing, who promote the 27-year-old Tszyu, would like to stage the fight in the final quarter of the year - and they have no issue with staging the contest in the United States.

“Obviously him (Charlo] being the undisputed champion, all the cards are in their favor,” No Limit Boxing CEO George Rose told Fox Sports News.

“Where we’re at at the moment is we’re pushing an Australian or US location. We’d love it in Australia, obviously they want the US location and if it is in the US we’d be pushing for LA or Las Vegas. I think the likely timing of it would be October-November.”

Tszyu is also rated at number two in the WBC and number three in the IBF and is undefeated with a record of 21-0 (15 KOs) while Charlo is 35-1-1- (19 KOs).

Tszyu made his United States debut in March, with a hard fought twelve round unanimous decision win over Olympian Terrell Gausha at The Armory in Minneapolis. The Aussie star was dropped in the very first round, but rallied as the contest played out and had Gausha in trouble several times in the second half of the bout.