A Chinese national flag flies at half-mast to mourn for martyrs who died in the fight against the novel coronavirus disease (COVID-19) outbreak and compatriots who died of the disease at the Consulate-General of the People's Republic of China in Christchurch, New Zealand, April 4, 2020. (Photo by Yu Gang/Xinhua)

A Chinese national flag flies at half-mast to mourn for martyrs who died in the fight against the novel coronavirus disease (COVID-19) outbreak and compatriots who died of the disease at the Consulate-General of the People's Republic of China in Auckland, New Zealand, April 4, 2020. (Photo by Huang Jinshuai/Xinhua)

A Chinese national flag flies at half-mast to mourn for martyrs who died in the fight against the novel coronavirus disease (COVID-19) outbreak and compatriots who died of the disease at the Consulate-General of the People's Republic of China in Sydney, Australia, April 4, 2020. (Consulate-General of the People's Republic of China in Sydney/Handout via Xinhua)

A Chinese national flag flies at half-mast to mourn for martyrs who died in the fight against the novel coronavirus disease (COVID-19) outbreak and compatriots who died of the disease at the Consulate-General of the People's Republic of China in Melbourne, Australia, April 4, 2020. (Consulate-General of the People's Republic of China in Melbourne/Handout via Xinhua)

A Chinese national flag flies at half-mast to mourn for martyrs who died in the fight against the novel coronavirus disease (COVID-19) outbreak and compatriots who died of the disease at the Chinese Embassy to Japan in Tokyo, Japan, April 4, 2020. (Xinhua/Du Xiaoyi)

A Chinese national flag flies at half-mast to mourn for martyrs who died in the fight against the novel coronavirus disease (COVID-19) outbreak and compatriots who died of the disease at the Chinese Embassy to Poland in Warsaw, Poland, April 3, 2020. (Xinhua/Chen Xu)