The 27-year-old joined the club for the 2017-18 season from Super Rugby side Blues and has made 23 appearances.

"It's a privilege to commit my future - it's an environment that is getting the best of out of me," Luatua said.

"There is huge ambition at the club to keep progressing and getting better, I'm excited to be a part of that."

New Zealand international Luatua has won 15 caps for New Zealand and also worked with head coach Pat Lam during his time at Blues.

"Steve is a pivotal character for us, on and off the field. His influence around the training ground and his performances on the field have earned him the respect of players, staff and supporters," Lam said.

"Securing his commitment at this early stage underlines the belief that we have within the club about what we can achieve. We're looking forward to seeing Steve continue to drive our progress towards our vision."