BEIJING -- With the resurgence of infections in neighboring countries, China's COVID-19 prevention and control efforts are facing increasing pressure, a health official said Wednesday.

Nine provincial-level regions in China have each reported more than 100 COVID-19 cases since August, with over 2,000 infections in Hainan, said Mi Feng, spokesperson for the National Health Commission (NHC).

The latest COVID-19 outbreak in Sanya, a coastal resort city in South China's Hainan province, is still evolving at a high level, said Mi.

The epidemic situation in provincial-level regions like Xinjiang, Inner Mongolia and Guangdong is evolving rapidly, Mi said, cautioning about the risk of community spread.

The NHC spokesperson added that the recently reported cases in the Tibet autonomous region also pose a high risk of spread.

The epidemic situation in some provincial-level regions that previously reported infections has been brought under control, according to Mi.

Noting that working groups have been dispatched to affected regions to aid containment efforts, Mi reiterated the importance to guard against imported cases and domestic resurgence and adhere to the dynamic zero-COVID policy.

As of Tuesday, 3.427 billion COVID-19 vaccine doses had been administered on the Chinese mainland. Nearly 239 million elderly people aged 60 or above had been vaccinated against COVID-19, the NHC spokesperson said.