China has promised not to punish New Zealand if it joins Australia's international inquiry into the origins of COVID-19, the Foreign Minister says.

Winston Peters says officials at the highest level of China's government have allayed fears that New Zealand's participation in the enquiry would result in consequences for exporters.

It comes just days after China fired a warning shot at Australia - which alongside the US is leading calls for an investigation - for its "dangerous" insistence on investigating the origins of the outbreak.