More than 13 million passenger trips in and out of Hong Kong will take place over the Christmas and New Year holidays with the majority via land borders, officials said on Friday.

The Immigration Department said about 11 million trips will likely be made through land boundary control points from Saturday to New Year's Day.

The number of departures via land is estimated to peak at 595,000 on Christmas Day and the inbound figure is likely to reach a high of 626,000 on December 29, officials said.

Border control points at Lo Wu, Lok Ma Chau and Shenzhen Bay are expected to be busy, authorities said.

"To cope with the anticipated heavy traffic during the festive period, the [Immigration Department] has minimised leave for frontline officers for flexible deployment and operation of extra clearance counters and kiosks," the government said.

"Additional security guards will also be deployed to provide crowd management support."

Officials also said further details will be announced "as soon as possible" regarding government requests to extend the service hours of two border checkpoints on New Year's Eve.