All Blacks coach Steve Hansen's hopes of winning a third successive World Cup have been boosted by flyhalf Beauden Barrett's decision to commit his immediate playing future to New Zealand Rugby until after the 2019 tournament in Japan.

The 25-year-old has been in career-best form this season, helping the Wellington Hurricanes to a maiden Super Rugby title and settling any arguments about who would succeed Dan Carter in the All Blacks' No. 10 jersey.

"It's great news for the team and great news for Beauden," Hansen said in a statement. "He's fast becoming one of 'the' players in the world.

"He's been a world-class player coming off the bench for some time, he's now graduated into starting test matches for us, and this year he's been nothing short of spectacular."

"He'll continue to grow — he's not the finished product yet, by any stretch of the imagination — but as he does, I think we'll see something pretty special, so it's nice to have him signed up and secure."

Barrett, who is the eighth player to sign through until the global showpiece in Japan, will also remain with the Hurricanes until 2019.