The SAR government late on Thursday condemned as “biased and misleading” criticism from the United State of its plans to bring in new national security legislation under Article 23 of the Basic Law.

In a statement, it dismissed comments from the US State Department, which had said earlier that it was concerned about what it described as “broad and vague” definitions of state secrets and external intereference in the legislation.

A Hong Kong government spokesman said: “The US was found conducting long-term covert surveillance around the world and even against the governments of multiple countries.

"A former US national security advisor even publicly admitted that he helped plan coups in foreign countries. It is simply unconvincing for the US government to comment at this juncture on the HKSAR's legislative proposals for safeguarding national security, especially those on offences relating to 'state secrets' and 'external interference'."

On claims from Washington that US citizens and residents could have their free speech limited by the legislation, the SAR spokesman added that giving extraterritorial effect to national security legislation was in line with international law and practice, including in the United States.

“The US even often abuses 'long-arm jurisdiction' and unilateral sanctions to target residents of other countries,” the spokesman added. "The smears by the US government on the extraterritorial effect of the Article 23 legislation are simply untenable."

The statement urged the US side to stay out of Hong Kong affairs, which are a matter for China alone.

Earlier, both Beijing and Hong Kong condemned criticism of the legislation by British Foreign Secretary David Cameron.

A one-month consultation on Article 23 legislation ended on Wednesday.