The government’s first delay was requested by Reed’s predecessor Angela Rayner, following a request for additional information from China about the plans.
Reed, who took over the housing role following Rayner’s resignation last month, has now requested additional time before a final decision needs to be made.
In a letter seen by the BBC, the housing department said more time was needed due to the “detailed nature” of responses from groups involved in the consultation, including China, the Met police and a local residents’ association.
China bought the site of the proposed new embassy, at Royal Mint Court, near the Tower of London, for £255m in 2018. At 20,000 square metres, the proposed complex would be the biggest embassy in Europe if it goes ahead.