Former New Zealand captain Daniel Vettori described the Black Caps' next World Cup game against Virat Kohli's India as "massive" but said they would not be defined by the result.
The fourth-ranked Kiwis are top of the 10-team points table with three wins in as many games. Hosts England, India, and Australia all have four points.
New Zealand, runners-up at the 2015 World Cup, have beaten Sri Lanka, Bangladesh and Afghanistan in the round-robin phase to put themselves in pole position for a semi-final spot.
"Three wins from three is a major confidence boost for New Zealand but the next game against India is simply massive," Vettori wrote in a column for the International Cricket Council.
"You know that matches against India are going to have a great atmosphere and be a real pressure situation," he added.
"India are perhaps the best team in the world and it's exciting to play in front of a big-match crowd that is so into the game and so passionate about cricket."
Kohli's team beat defending champions Australia by 36 runs in front of thousands of India fans at the Oval on Sunday to make it two wins out of two.
Vettori said the New Zealand players would have to deal with vociferous backing for the Indian side at Trent Bridge on Thursday.
"Lots of the guys will have experienced that in the subcontinent but to have that in England is going to be something that's new to them and something they need to get used to as the tournament goes on, particularly if they want to reach those semi-finals," he said.
"Because they've performed so well for a long time, New Zealand won't be defined by the result or performance in this game, win or lose."
Pacemen Matt Henry, Lockie Ferguson and Trent Boult did the damage for New Zealand in their first two victories, against Sri Lanka and Bangladesh.
But all-rounder Jimmy Neesham turned out to be an unlikely hero against minnows Afghanistan, claiming five wickets.
"You can see New Zealand want to go with two all-rounders and they really back their batting, so these types of performances just give them another option for how they play their game," said Vettori.