New Zealand's parliament unanimously declared on Wednesday that severe human rights abuses were taking place against Uyghur people in China's Xinjiang region, spurring the Chinese embassy to decry the move as interference in internal affairs.

All parties discussed and supported a motion by New Zealand's smaller ACT Party, but only after it was revised to drop the word "genocide" from the text.

In parliament, ACT's deputy leader, Brooke van Velden, said she had to insert the phrase "severe human rights abuses" in order to secure the approval of the ruling Labour Party, led by Prime Minister Jacinda Ardern.

"Our conscience demands that if we believe there is a genocide, we should say so," Van Velden added.

China, which denies all accusations of rights abuses in the far western region, expressed "strong dissatisfaction and firm opposition" to the motion, its embassy in Wellington said in a statement.

"Using Xinjiang-related issues to pressure China is futile and will only undermine mutual trust between the two sides," it added, calling the move gross interference in internal affairs.

New Zealand's Foreign Minister Nanaia Mahuta defended the government's decision not to use the term "genocide", saying it had raised concerns several times with China, but had not formally designated the situation as constituting a genocide.

"This is not due to a lack of concern," added Mahuta. "Genocide is the gravest of international crimes and a formal legal determination should only be reached following a rigorous assessment on the basis of international law."

She added that New Zealand, in concert with other governments, would keep up its calls for China to provide meaningful and unfettered access to the United Nations and other independent observers to ascertain the situation.

Nations such as the United States and Canada have declared China's actions in Xinjiang as genocide, but Australia's parliament stopped short of a similar move this year.