Ms Ardern's popularity has started increasing in preferred prime minister polls to about three or four per cent but she has said she does not want the top job herself.
Mr Little dismissed commentary that Ms Ardern could have been a threat to his leadership if in the deputy's role.
"My leadership style ... is to develop and nurture talent, I've always done that, I'll continue to do that. I don't feel threatened by that."
Ms Ardern says she did not want Labour's deputy leader job because she believed Annette King should keep it and she wanted to focus on winning the Auckland Central electorate .
"[Andrew] is right that I did not seek the role because in my mind it was clear to me we had a great team, a great leadership team, it didn't seem there was any kind of vacancy for me to put my hand up."
She would not say whether she would have taken the role if Mr Little asked her.
"It's a hypothetical. I was always willing to do whatever job Andrew says I'm best for."
She said she did want to focus on winning Auckland Central.
"I do have a big job ahead of me. I am in the most marginal seat in the country and I am determined to win that seat."
National's Nikki Kaye has beaten Ms Ardern in the seat twice but her majority last year was just 600 votes.
Ms Ardern said she believed it was an important electorate to win. It meant Labour's leadership team lacked Auckland representation - the most critical voting patch in the country.
Ms Ardern did not believe that was the only factor.
"Where they are geographically located is only one factor and I do genuinely believe they're doing a really good job."
She said Ms King was a mentor to her and a strong, stable leadership pairing was important.
She said speculation about whether her apparent increasing popularity was a threat to Mr Little was simply that and did not reflect any ambition she had.
"I've made it clear my ambition is simply to be a contributing member of the Labour Party. I enjoy the roles I have. I get to make a contribution I want to make, so I feel very positively about my position in the party."
Mr Little said his primary aim was a strong Labour Party and caucus.
He conceded it meant the leadership team was "very Wellington heavy" and he was conscious of that issue.
Mr Little, Ms King and the third ranked finance spokesman Grant Robertson are all Wellington based.
He said that would partly addressed in the reshuffle and he had made it clear to Ms Ardern that her work raising the profile of Labour in Auckland was critical. Currently the top ranked Auckland is Phil Twyford who is fifth ranked.
Soon after becoming leader last November, Mr Little appointed Ms King as an interim deputy because of her experience while he bedded in in his new role, but said at the time he intended to replace her after a year.
Today he said they had worked well as a team and it had given confidence to the caucus.
"I don't think there's any appetite to change that. I think the combination of Annette and myself is needed to continue to consolidate and get the benefits from what we've got in caucus."
He said she was "naturally thrilled" about staying in the role. Ms King is overseas and Ms Ardern has not yet commented.
Mr Little has struggled to get traction in the polls as leader - he was at eight per cent in this week's One News Colmar Brunton poll. He acknowledged that and said he was focussing on the issues, the performance in Parliament and reaching around the country.
"That's all I can focus on, it's what I'm doing, the feedback is good and we're going to continue that."
When he set out his initial shadow Cabinet, he made it clear the MPs were on performance watch and he would follow up with a reshuffle in a year.
He said that reshuffle was still to be finalised but confirmed Grant Robertson would keep the finance portfolio. Other MPs had been asked whether they were happy in their current roles.
Ms King is MP for Rongotai, the electorate in which Mr Little lives although he is a List MP and only just made it back into Parliament last year. Mr Little said he had no discussions about where he might stand in 2017.
Being a List MP freed him up to move around the country more, although that did not mean he would not stand in an electorate.
For the past two elections he has stood in New Plymouth, held by National's Jonathan Young.
