WASHINGTON, Jan 25 (Reuters) - The US State Department is preparing to authorise departures for American diplomats and their families in China who wish to leave due to the US government's inability to prevent Chinese authorities from subjecting them to intrusive pandemic control measures, sources told Reuters.

Two sources familiar with the issue said the US Embassy on Monday (Jan 24) had sent the request to Washington for formal sign-off, as China ramps up COVID-19 containment protocols ahead of the opening of the Beijing Winter Olympics in less than two weeks.

The sources, speaking to Reuters on the condition of anonymity due to the sensitivity of the issue, added that some embassy staff are upset that the US government has been unwilling or unable to protect American officials from strict quarantine measures. The rules include possible forced admittance to COVID-19 fever clinics and separation from children.

The State Department did not respond to repeated requests for comment, and it is unclear if it had approved the embassy's request.

One person said the US Embassy conducted an internal survey showing that as many as 25 per cent of staff and family members would choose to leave China as soon as possible.

Home quarantine for diplomats should be a baseline requirement, and admission to Chinese fever clinics and hospitals should be voluntary, the person said, adding that the US government should have imposed retaliatory measures for such requirements but failed to do so.

A second person said embassy leadership had failed to get appropriate assurances from China on the treatment of US diplomats throughout the pandemic.

In the early months of the pandemic, the US government evacuated about 1,300 US diplomats and family members from China, and the two governments remained at an impasse for months over testing and quarantine procedures for officials.

In general, China has required foreign diplomats to abide by pandemic control rules like the regular public, including weeks of quarantine in centralised government facilities, where individuals do not have freedom of movement.

China has quickly stepped up measures to block the further spread of COVID-19 as the Feb 4 opening of the Beijing Winter Olympics approaches, though flare-ups of the virus have persisted throughout the city.

One Beijing district on Tuesday was set to begin a new round of tests among its roughly 2 million residents.

China's nationalist Global Times tabloid called the State Department's consideration of the policy a "dirty trick" intended to disrupt China's hosting of the Olympics.