Hong Kong on Friday extended a ban on incoming flights from eight countries, including the UK and the US, and imposed one on Nepal until March 4, with the government citing concerns over a growing Covid-19 outbreak.
The other countries are Australia, Canada, France, India, Pakistan and Philippines.
Flights to Hong Kong are down 90 per cent and hardly any are allowed to transit as the financial hub isolates itself from the world in the hope it can contain a coronavirus outbreak, even though new infections are overwhelmingly local transmissions.
New daily infections rose to at least 1,325 on Friday, health authorities said.
"Our healthcare system is overloaded, it’s really beyond capacity," said Chuang Shuk-kwan, a senior health official.
She said there were separately at least 1,500 preliminary positive cases.
Hospital beds for Covid-19 patients in the global financial hub are already at 90 per cent occupancy, data from the city's Hospital Authority showed, while isolation facilities were also nearing their maximum.
China's central government is "highly concerned" about the safety and health of residents as well as the economy and people's livelihoods, a spokesperson for the Hong Kong and Macau Affairs Office (HKMAO), which comes under China's State Council or cabinet, said in a statement.
It said it would help support Hong Kong's fight against the disease.
"As long as Hong Kong asks, the motherland will surely respond ... Hand in hand, we will surely be able to overcome the epidemic soon," it said.
The Chinese government will help improve Hong Kong's testing capability and set up another quarantine facility, the South China Morning Post reported, citing a Beijing-based source.
Beijing is also preparing to send thousands of medical and lab workers and millions of test kits to Hong Kong, with the daily coronavirus screening capacity to be increased from 100,000 tests to 300,000 tests.
Hong Kong has seen a 10-fold rise in cases since February 1 and medical experts warn the city could see 28,000 daily infections by the end of March, with the unvaccinated elderly a particular worry.