(CNN) The US government is arranging a charter flight to evacuate American diplomats and citizens from the Chinese city that has become ground zero for a new deadly strain of coronavirus, a US official with knowledge of the matter told CNN Saturday.

The United States has a contract with a transporter to evacuate about three dozen diplomats and their families from the US consulate in Wuhan, China. The consulate is closed and all US diplomats are "under ordered departure," the official said.

Details of the flight plan are still being finalized -- for example, officials were still deciding between a narrow-body Boeing 737 and a wide-body Boeing 767 -- and the source said "a lot depends on what the Chinese authorities will allow us to do," adding that Beijing has been "very cooperative." The Wall Street Journal first reported the planned evacuation.

The State Department and White House have not yet responded to CNN's request for comment on the matter.

The US consulate in Wuhan reached out to Americans registered with the consulate and offered them seats on a flight, the official told CNN. The flight will have medical personnel aboard to treat anyone with the virus and make sure it is contained.

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