Chief Executive Carrie Lam said on Tuesday that Hong Kong is only going by the book when disallowing foreign consulates from offering protection to people with dual citizenship here.
This comes after the British consulate said it may not be able to assist people who hold both British and Chinese nationalities here.
Canada also revealed that the SAR authorities forced a dual citizen to choose one nationality, enforcing what the diplomats said was a little-used regulation for the first time in decades.
But speaking ahead of the weekly Executive Council meeting, Lam cited the Vienna Convention, saying Hong Kong is only following international practice.
"If that particular person is in one of the places or countries which he possesses one of his national status, then he will not be eligible for this sort of [foreign] consular protection including consular visits," she said.
"That is the general rule applied to all countries and places."
The CE added that the National People's Congress Standing Committee made a decision in 1996 that dual nationals would be viewed as Chinese nationals in the SAR after the handover, and therefore ineligible for consular protection provided by other countries.