"Mic check, mic check one...two..is this thing on?" read the tweet sent out Saturday.
The account was verified a few hours after the tweet was posted, The Hollywood Reporter said.
During a recent interview, Bass would not confirm or deny the rumored reunion.
"It's amazing to see the reaction out there on Twitter and social media [and] how many people are supporting 'N Sync," he said.
The group's last televised performance came at the 2003 Grammy Awards, and the VMAs will take place at Brooklyn's Barclays Center Sunday.
Timberlake is also set to receive the Michael Jackson Video Vanguard Award, the VMA's version of the lifetime achievement award.