Beaten out for the All Blacks' top job by Ian Foster in 2019 - the six-time Super Rugby winning coach is contracted with the Crusaders to the end of next season.
Robertson told the Rugby Pod - a podcast hosted by ex-Scotland international Jim Hamilton - that international rugby is where his future lies and he wants to be coaching at the 2027 World Cup.
"I want to win a Rugby World Cup. But I want to win it with two different countries. I think that would transcend (the game).
"It would be great to win a Rugby World Cup with your own country which I want to do, that is the foremost thing but I would also like to do it with another country - not sure what order it might be, not sure how that plays out as though decisions are not mine!".
Robertson says he'd like to be known as a coach that players want to play for and is "open to offers" if New Zealand Rugby doesn't want him to lead the All Blacks coach.
"(The All Blacks) is one job but when someone doesn't give it to you you have to think differently (and look) at what opportunities are out there so I am open - if New Zealand Rugby want me 'Great!'.
"But if there is another country... I just want to get to two or three (World Cups) and really test myself."