China's Xi writes thank you note to Bill Gates for virus pledge

Earlier this month the Bill and Melinda Gates Foundation committed up to $100 million for the global response to the outbreak.

"I deeply appreciate the act of generosity of the Bill & Melinda Gates Foundation and your letter of solidarity to the Chinese people at such an important moment," Xi wrote in the letter, according to official news agency Xinhua.

China is at a "critical moment" in the fight against the outbreak, he said.

Millions remain under lockdown in central Hubei province, where the virus emerged in December, although new hotspots were found in several prisons and hospitals on Friday.

Nearly 400 new cases were reported nationwide in China on Saturday -- less than half the number of new cases the previous day.

"We have rallied the whole nation and adopted a string of unprecedented measures to contain and mitigate the epidemic and treat the sick," Xi wrote.

"These extraordinary measures are delivering substantial results," he said.

The Gates Foundation said the funding will be used to strengthen detection, isolation and treatment efforts, including protecting at-risk populations and developing vaccines and diagnostics.

The foundation said it would direct $20 million to organizations like the World Health Organization, the US Centers for Disease Control and Protection, the National Health Commission of China and the Chinese Center for Disease Control and Prevention.

Photo: AFP/File / Ludovic MARIN