Crusaders coach Scott Robertson will succeed Ian Foster as head coach of the All Blacks after this year's World Cup.

He has been appointed on a four-year deal which will run to the end of the 2027 World Cup in Australia.

"It's an honour to be named as the next All Blacks head coach," said 48-year-old Robertson.

"It's a job that comes with a huge amount of responsibility, but I'm excited by the opportunity to make a contribution to the legacy of the black jersey.

"To represent your country, as a coach or player, is the ultimate honour in sport and it's humbling to be given that opportunity. I can't wait."

Foster came under pressure last year after a run of poor results, including a home series defeat by Ireland and the All Blacks' first loss in New Zealand to Argentina.

Following a review in August 2022, the New Zealand Rugby (NZR) board agreed he should remain as coach until after the World Cup.

He then guided the side to an eighth Rugby Championship title and an undefeated tour of the northern hemisphere at the end of last year.

Earlier this month, Foster said he would not reapply for the job when his contract expires after this year's World Cup, which runs in France from 8 September to 28 October, but criticised NZR for conducting its search in the middle of his tournament preparations.

NZR said "significant competition for elite coaching talent" meant they could not delay.

"The decision to appoint the next All Blacks head coach ahead of the World Cup was not taken lightly, but we believe it was the right decision for New Zealand Rugby and the All Blacks and will set the team up for future success," said NZR board chair Patsy Reddy.

Robertson, nicknamed 'Razor', played 23 Tests as a back-row forward and has guided the Crusaders to six Super Rugby titles since taking over the South Island team in 2017.

New Zealand are currently ranked third in the world behind Ireland and France and face a period of rebuilding after the World Cup.