"We've seen it in the Northern Hemisphere, Eddie Jones is very focused on 2019, and he's looked at what the All Blacks are doing.
"They've [England and Ireland] looked at what the All Blacks are doing, and they're making changes, not only just in the game plan, but the way the players are playing."
The 54-year-old went on to state that the Northern Hemisphere, and England in particular, have the number and quality of players within their ranks to make themselves a genuine threat for the All Blacks' World Cup hopes in two years' time.
"I think there's been a real shift in terms of the calibre of players, and that's the one thing England especially has, they have more players than anyone else in the world, they have a lot of money to throw at the game, and they're becoming very competitive.
"I think in 2019, we're going to have some serious contenders, and they won't all be from the southern hemisphere, there will be some serious contenders from this part of the world."
The All Blacks have not played England since November 2014, and are scheduled to face the second-ranked side in the world at the end of next year in London, while the New Zealander's most recent encounter against Ireland came ten months ago in a 21-9 victory in Dublin.
The Kieran Read-captained side currently have just one Northern Hemisphere country in their pool for the 2019 World Cup, drawn alongside Italy as well as Rugby Championship rivals South Africa in Pool B.