Christopher Luxon has walked back claims made by one of his ministers about the Greens, before then suggesting - wrongly - that they originated from the media.

Trade Minister Todd McClay, on Wednesday, accused the Green Party of "joining with foreign actors to attack New Zealand" in regards to a climate change complaint lodged with the European Commission.

The Greens quickly denied any involvement and McClay provided no evidence.

Asked for evidence on Friday, Luxon put the responsibility back on reporters to investigate whether the Green co-leader Chlöe Swarbrick had any involvement.

"That'd be up for you guys to ascertain whether she has or hasn't," he said.

Luxon then suggested that the media had first raised the possibility of Swarbrick's involvement.

"I'm just saying that's not appropriate if that's the case. But equally, I'm sure she hasn't done that."

Told that the Green Party had not be involved, Luxon replied: "Great, great. That's good to hear. That's good that you've bottomed that out. Well done, well done... Good job."

In a statement, Swarbrick said McClay had provided "zero evidence" to support his "bizarre claim". She said Luxon's government was blaming everybody else for the consequences of its policy to "shred climate action".

"The worst absurdity of all of this is that the most fired up the government has got on climate action is trying to cover their tracks by attacking everyone else, instead of doing the responsible thing."

RNZ has asked McClay's office for evidence for his claim.

Luxon said he was not worried about the international complaint because New Zealand upheld its free trade obligations.

"It's very disingenuous to suggest otherwise. We take that incredibly seriously. We are a free trading nation. We respect our FTA agreements and what's in them, and we'll continue to do so.

"When any other country gets to 96.3 percent renewable electricity, then you might want to throw some stones at us.

"But until then, I'm not that interested in what Laura Clarke or anybody else says, frankly."

Clarke, a former British high commissioner to New Zealand, told RNZ’s Morning Report on Friday that the legal action put New Zealand's 100 percent pure brand at risk.