Wellington - Wales coach Warren Gatland has been ruled out as the next All Blacks coach, even though he has not publicly declared an interest in replacing Steve Hansen.

Gatland and Hansen finish their terms as coaches of Wales and New Zealand after the two semi-final losers battle for the Rugby World Cup bronze medal in Tokyo on Friday.

Although Gatland, a New Zealander, has an impressive record as the coach of Wales he is scheduled to coach the British and Irish Lions on their 2021 tour of South Africa.

"It's impossible to coach the All Blacks and the Lions in a four-year period," New Zealand Rugby chief executive Steve Tew told Radio Sport on Monday, adding they did not know "if he is going to apply, or what he has written into his current contracts."

Gatland has been confirmed to take over the Waikato Chiefs Super Rugby side next year and will take a sabbatical the following year to handle the Lions.

Tew said a four-person panel would be appointed after the World Cup to interview candidates to replace Hansen but the New Zealand Rugby board would have the final say.

Current All Blacks assistant coach Ian Foster, Crusaders coach Scott Robertson and Japan coach Jamie Joseph are considered the frontrunners for the position.