Sukar, 24, joined the Blues during the 2017/18 season, and has impressed during his time at the club.
The new contract will see the defender go into his fourth year at the club.
He said: "I'm really happy to have signed a new deal, and from the few games we played last season, I feel that we've got a really good team.
"I really enjoy playing for both of the managers - they're two great men. In fairness, I just enjoy playing for the club in general.
"The club is great and that includes the fans and the board. I'm grateful that I've been given the opportunity to sign for another year."