Sonny Bill Williams says he's leaving New Zealand rugby with a sense of regret after deciding to honour a handshake deal he made to return to rugby league four years ago.
The 26-year-old will leave after the Super Rugby season and will return to the NRL in Australia next year after a lucrative stint playing rugby in Japan.
Williams says would have preferred to have stayed with the Chiefs and All Blacks beyond this year if he had not made the earlier commitment to an NRL club.
Williams won't play for the All Blacks again this year or next but he hasn't ruled out returning in 2014, in time for the 2015 rugby world cup.
He confirmed a deal with the Japanese rugby club Panasonic Wild Knights and will leave for Japan following the Super Rugby competition, in time for the start of the Japanese Top League competition in September.
The All Blacks Head Coach Steve Hansen says while Williams has been with New Zealand rugby for only a short time, his contribution has been immense.
He says this season has seen the birth of Williams as a rugby player, with his game understanding now complementing his array of skills.
Williams will return to the National Rugby League in Australia next year where the Sydney Roosters are widely tipped to get his services but the dual international says no deals have been signed.
Williams has played 17 Tests for the All Blacks and more than 20 Super Rugby matches for the Chiefs and Crusaders.
The NZRU chief executive Steve Tew says the midfielder would be welcomed back to New Zealand rugby with open arms.