Chasing 261, India were bowled out for just 198 inside 47 overs after a quickfire 71 from Harmanpreet. Powar said India would require substantial contributions from the other senior players for better results in the forthcoming games.
"I expect everyone from the top five to be consistent," he said. "I want seniors to be putting their hand up like Mithali, Smriti, Jhulan, and win us the game single-handedly because their participation in the wins and their contribution in the wins will rub on to the younger players because we have inexperienced players as well as experienced players [in the squad] … So, it's not that I have to react to form [of players]. I'm trying to build players here who will win India [the] World Cup."
The defeat against New Zealand will affect India's chances of reaching the semi-finals of the eight-team World Cup. They are currently placed fifth on the points table with one win - against Pakistan - from two games, and more formidable teams await them in the tournament. To rebound from Thursday's defeat, Powar said, India will need to improve their run-scoring in the early stages and perform better as a unit.
"It was one of those days where things didn't go our way," Powar said of India's loss against New Zealand. "And honestly, I was also surprised the way we batted [in the first] 20 overs, and if you look back at the last six games which we played against New Zealand, we were executing our plans well.
"I think it is the pressure of a World Cup, but I don't want to give any excuses. It is the right time to put your hand up and put up performances because we've been training for the last six months. We've been to England, Australia, [and] we've been to New Zealand early, so we got every practice opportunity which we needed, so it is time as a group to stand up and deliver.
"If you've watched us [in the] last six months or [the] last three tours, we've been improving as a batting unit. [Earlier], we used to struggle to get to 220. [But, more recently] we've been scoring 270s and 280s. Again, it is up to the individuals, like I [have] always said. The players go out there and face that pressure and come out of it with their own skills and character."
India face red-hot West Indies in their next match, on Saturday, in Hamilton again. One of the three teams to enter this World Cup via the qualifying route, West Indies have already caused two upsets in the tournament, downing the hosts and defending champions England in their first two outings. With three in-form offspinners - Anisa Mohammed, Hayley Matthews, and Stafanie Taylor in their XI - Powar hinted at a relook at the make-up of India's top order, which saw three left-hand batters on Thursday.
"Yes, we will definitely look at it - three left-hand batters in a row. Two [of them] inexperienced, I agree with that, barring Smriti," he said. "Maybe, we have taken a wrong call. We accept that; that is not a big deal. I think moving forward, we need to address that.
"I don't think three left-handers in a row makes a difference in every match, but going forward, yes, we are going to look at it tactically. It gives an advantage to opponents to set up the plan easily, and the left-right batter combination allows us to get to a batting rhythm and bowling to left-right combination is kind of difficult for bowlers also."
West Indies, for their part, are eyeing to exploit any lack of variety in India's top three, fast bowler Shakera Selman said on match eve.
"We obviously have discussed it as a team. We saw them change from Shafali Verma to Yastika Bhatia at the top," Selman said. "I think our offspinners are probably licking their lips at that batting line-up. But I have no idea what change they'll make tomorrow. Good thing for us is Shafali didn't do well in the practice game against us either. So maybe it's more of an issue for the Indian team to figure out whom they're going to send against us tomorrow."
As for a rejig in India's batting order, asked if he and captain Raj, who has been prolific at No. 4 on the recent tours, have considered handing her opening duties or a promotion to No. 3, Powar said: "We have healthy discussions about it. We think about how to address blocks of overs because a 50-over game is a long game. It's not T20s where you push players around here and there. I think we need to discuss as a unit that 50 overs should be played by our best batters. So going forward, that is what I will push for. Let's see what happens."
Annesha Ghosh is a sub-editor at ESPNcricinfo. @ghosh_annesha