Cathay Pacific Airways Ltd on Monday warned passenger capacity could be cut by about 60% and monthly cash burn may rise if Hong Kong installs new measures that require flight crew to quarantine for two weeks.

Hong Kong's flagship carrier said the expected move will increase cash burn by about HK$300 million ($38.70 million) to HK$400 million per month, on top of current HK$1 billion to HK$1.5 billion levels.

Hong Kong is set to require flight crew entering the Asian financial hub for more than two hours to quarantine in a hotel for two weeks, the South China Morning Post reported last week, citing sources. 

"The new measure will have a significant impact on our ability to service our passenger and cargo markets," Cathay said in a statement, adding that expected curbs will also reduce its cargo capacity by 25%.

The airline, in an internal memo seen by Reuters, requested for volunteers among its crew who could fly for three weeks, followed by two weeks of quarantine and 14 days free of duty, adding it will be a temporary measure and not all its flight will require such an operation.

"We continue to engage with key stakeholders in the Hong Kong Government," the memo said.

In an emailed response to Reuters, a Hong Kong government spokesperson said: "In the light of the evolving pandemic situation locally and internationally, the Government will keep reviewing and refining the arrangements applicable to different categories of exempted persons, including air crew, with reference to all relevant considerations."

Separately, a company spokeswoman said the airline could not detail the impact on vaccine transport specifically in terms of cargo shipments.

The aviation industry has been hit hard by the COVID-19 pandemic as many countries imposed travel restrictions to contain its spread.

In December, Cathay's passenger numbers fell by 98.7% compared to a year earlier, though cargo carriage was down by a smaller 32.3%.

($1 = 7.7512 Hong Kong dollars)

(Reporting by Shriya Ramakrishnan in Bengaluru; Additional reporting by Jamie Freed in Sydney and Twinnie Siu in Hong Kong; Editing by Bernard Orr, Arun Koyyur and Mark Potter)