At least 1,355 people have now died and almost 60,000 have been infected in China after Hubei's health commission reported the new numbers.
The death toll from the coronavirus outbreak in China has reached 1,380.
The province, the epicentre of the outbreak, had 242 more deaths and over 14,800 new cases on Thursday.
The health authority said an accumulated total of 63,851 people have been infected by the coronavirus.
Mike Ryan, head of WHO's health emergencies programme, said more than 14,000 new cases reported in Hubei province on Thursday came after a change to include results from quicker computerised tomography (CT) scans that reveal lung infections, rather than relying just on laboratory tests to confirm cases. Though Chinese authorities initially stipulated that only Canadian passport holders would be able to leave the quarantined region, they seem to have relaxed that rule, Champagne said, but he did not elaborate on whether Canada would make arrangements to fly more of them out.
US officials escalated criticism of China's response to the coronavirus outbreak, questioning the government's transparency.
The National Health Commission said the new criteria would only apply to Hubei.
Hubei had previously only allowed infections to be confirmed by RNA tests, which can take days to process. The NHC did not account for a discrepancy of one case, as it had reported that the total accumulated number as of Tuesday was 44,653.
"We've seen this spike in the number of cases reported in China, but this does not represent a significant change in the trajectory of the outbreak."
Vietnam has locked down a community northwest of Hanoi because of a cluster of COVID-19 cases.
The online newspaper VN Express cited a senior official of Ving Phuc province as reporting an increase in cases in Son Loi commune. Infectious disease specialist Dr. Isaac Bogoch explains how the report got it wrong.
Japan confirmed its first death from the virus on Thursday. Provincial authorities said there are about 37,000 patients in hospital, 1,685 of whom are in critical condition.
Meanwhile, another cruise ship, the Westerdam, finally anchored off the waters of Cambodia Thursday after being at sea for almost two weeks. No cases of the viral illness have been confirmed among its 1,455 passengers and 802 crew members, according to operator Holland America Line.
Prime Minister Hun Sen agreed to let the Westerdam dock after Thailand, Japan, Taiwan, the Philippines and Guam barred the ship over fears it might spread a virus.
Hong Kong, where 50 cases have been confirmed, extended the suspension of schools to March 16. She was part of a group of eight Vietnamese workers for a Japanese company who had been training in Wuhan, the epicenter of the outbreak.