Sources with direct knowledge tell TMZ … Justin and his team have yet to comment respective proposals for a possible *NSYNC stadium tour next summer — this despite the fact Lance Bas, Chris Kirkpatrick, Joey Fatone And JC Chasez have all responded with interest after several promoters gave their pitches 4 months ago.

In other words… JT is the only one who hasn’t been in on these conversations. And we hear the others are disappointed with Justin’s radio silence.

The reason… According to our sources, the other *NSYNC guys felt that the past year was a teaser for the band’s fans that something big was coming – and that a 2025 tour would coincide with the band’s 25th anniversary… perfect timing in their eyes.

We hear that Sony was also hoping for a big push on the 25th anniversary, because of the band’s back catalog. As we reported, the band major music labels are sniffing around to produce a new single or album.

Remember, the *NSYNC guys have been out there supporting JT a lot this past year, all to promote/supplement his projects, but from their perspective… they’re not getting anything in return.

Sources close to JT tell us he’s not in talks with promoters about a potential *NSYNC stadium tour because he’s currently focused on his nearly sold-out world tour and he’s just busy.

Still, an *NSYNC reunion could still happen. Our sources tell us that Lance coordinated a meeting between Chris, Joey, and JC in NYC on Monday to discuss the future of the band, and what it would potentially look like moving forward without JT if he were to pass up this opportunity.

We’re told Justin has been approached to be on the show today, however, our JT sources say he can’t be in New York because he’s in Europe preparing for his show in Poland later this week.