China hit back against what it called "irresponsible" comments by the head of the World Health Organization, who described the country's uncompromising and increasingly painful "zero COVID" policy as "not sustainable."

The response from the Foreign Ministry came after WHO Director-General Tedros Adhanom Ghebreyesus said he had been discussing with Chinese experts the need for a different approach in light of new knowledge about the virus.

“When we talk about the ‘zero-COVID,’ we don’t think that it’s sustainable, considering the behavior of the virus now and what we anticipate in the future,” Tedros said.

The policy has placed hundreds of millions of people across dozens of cities under various degrees of movement restrictions, most dramatically in Shanghai, causing significant economic damage in China and beyond and fuelling widespread frustration.

Officials in Shanghai, now in its sixth week under a sweeping lockdown, said on Wednesday that half of the city had achieved "zero COVID" status, but restrictions would remain in place.

China’s Foreign Ministry spokesperson Zhao Lijian said at a daily briefing Wednesday, “We hope that relevant people can view China’s policy of epidemic prevention and control objectively and rationally, get more knowledge about the facts and refrain from making irresponsible remarks.”

“The Chinese government’s policy of epidemic prevention and control can stand the test of history, and our prevention and control measures are scientific and effective,” Zhao said. “China is one of the most successful countries in epidemic prevention and control in the world, which is obvious to all of the international community.”

The incident marked a rare public show of friction between China and the WHO, which has been accused of succumbing to Chinese pressure to avoid criticism and awkward questions about the origins of the virus that was first detected in the central Chinese city of Wuhan in late 2019.

Tedros' comments were not covered in China's state media and were censored on social media, with the only official response coming at a regular foreign ministry news conference.