A spokesperson for China's foreign ministry says she was surprised that New Zealand expressed concern about the promotion of a doctored image of an Australian soldier.
A Chinese official had tweeted a picture of a soldier holding a knife to an Afghan child's throat.
The falsified image is in reference to a recent inquiry in Australia that found 39 of its soldiers were responsible for unlawful killings of Afghan civilians.
Prime Minister Jacinda Ardern told reporters New Zealand observes closely relationships with its major trading partner, China, and others, and will speak up on issues that it has concerns about. "We will stick to our independent foreign policy, but that doesn't stop us observing what's happening with others."
In a press briefing, China's Foreign Ministry spokesperson Hua Chunying said she was "very surprised" when she read in the news that New Zealand had expressed concern.
"Does this matter have anything to do with New Zealand? Can it be that New Zealand agrees with or even supports Australia's deeds?" she said.
"Like I said, we have pictures and other facts including the Australian Defense 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."
Australian Prime Minister Scott Morrison has demanded the Chinese government delete what he described as a "repugnant" tweet attacking the Australian Defence Force in the wake of the landmark war crimes inquiry.
China's embassy in Australia said politicians there had "misread" the tweet and were trying to stoke nationalism.
On Tuesday, the tweet was pinned to the top of China's foreign ministry spokesman Zhao Lijian's social media account, and China's Global Times newspaper, known for nationalistic views, interviewed the Chinese artist who created the image.
"The rage and roar of some Australian politicians and media is nothing but misreading of and overreaction to Mr Zhao's tweet," the Chinese embassy in Canberra said in a statement on Tuesday.
Australia was seeking to "stoke domestic nationalism", and "deflect public attention from the horrible atrocities by certain Australian soldiers", it said.
- additional reporting from Reuters