Her comments follow criticism that New Zealand was bleating like an Australian sheep in the Global Times, a daily newspaper considered to be a mouthpiece for the Chinese Communist Party.
And overnight, China's Foreign Ministry spokeswoman Hua Chunying said she was "very surprised" to read in the news that New Zealand had raised concerns.
"Does this matter have anything to do with New Zealand? Can it be that New Zealand agrees with or even supports Australia's deeds?
"Like I said, we have pictures and other facts including the Australian Defence Department's report on this matter. The truth and the merits of this matter are crystal clear.
"If needed, our journalist friends, China and Australia can all provide these materials to New Zealand."
Ardern said she didn't believe raising concerns had hurt China-NZ relations.
"This mature relationship we have with China, they expect New Zealand to raise concerns when we see them."
Nor was raising concerns a sign that New Zealand was siding with Australia.
"We certainly don't see it that way. If we saw a visual representation published by Australia that was incorrect, a doctored image for instance, we would raise concern also.
"For us, it was a matter of principle."
Asked if she would condemn the Australian war crimes, she said: "We're already seeing Australia taking action on that and responding to it."
Several Australian Defence Force members are facing the sack.
Australian Prime Minister Scott Morrison called the image "truly repugnant" and demanded an apology.
But Hua Chunying defended the use of the photo.
"A falsified photo? Australia accuses China of using a falsified or fake photo, and even of spreading false information, but such an accusation is in itself a false one.
"The graphic depicts a fact because its creation is based on the inquiry report issued by the Australian Defence Department."
She did little to ease tensions between Australia and China, calling Australia "unbelievably arrogant hypocrites".
"[Australia] wants to turn that into a tough-on-China position.
"China is treated with this 'I can, but you cannot' approach. For example, I can have 5G technologies, but you cannot; I can have a bigger economy than yours, but you cannot; I can make accusations against you while siding with 'Tibet independence' forces, 'Taiwan independence' forces, Xinjiang separatist forces, and the opposition and violent criminals in Hong Kong, but you cannot.
"This 'I can, but you cannot' approach reflects the attitude of those unbelievably arrogant hypocrites. Their real motive is to deprive China of the right to tell facts and truth."
