The government on Wednesday said a new regulation will be gazetted this week requiring airlines to pass personal data on passengers flying to Hong Kong to the SAR authorities.

The Security Bureau said the new rule will make it easier for immigration officials to prevent "undesirables, including potential non-refoulement claimants" from boarding flights to the city.

A statement said the regulation, under the Immigration Ordinance, will give legal backing to the implementation of an Advance Passenger Information (API) system which is required under the Convention on International Civil Aviation, to which China is a signatory.

"The API system is an electronic communications system whereby personal data of travellers (API data) and their respective aircraft information are collected and transmitted by the airline concerned to the border control agency prior to/after flight departure, so that the border control agency can immediately conduct a risk assessment of border security for issuing boarding directions in respect of the travellers," the statement said.

Flights departing from Hong Kong are not affected by the new regulation, which will be published in the Gazette on Friday and tabled to Legco for negative vetting on March 29.

The Security Bureau said the API system is currently under development and is set to be rolled out in phases from the third quarter of next year.