CHINA accused the United States consul general in Hong Kong of interfering in its internal affairs on Saturday after he said the city’s freedoms were eroding — and warned the US not to cross political “red lines.”

Consul general Gregory May gave a video address last month in which he expressed concern over alleged diminished freedoms in Hong Kong and said its reputation as a business centre depended on adherence to international standards and the rule of law.

The Ministry of Foreign Affairs Office in Hong Kong said its commissioner Liu Guangyuan met with Mr May recently to express objections to his “inappropriate” words and deeds.

“Liu also drew three red lines for the US consul general and the US consulate general in Hong Kong, which is not to endanger China’s national security, not to engage in political infiltration in Hong Kong, and not to slander or damage Hong Kong’s development prospect,” Mr Liu’s office said.

The office added that Mr Liu had also urged the US consul general to abide by diplomatic ethics.

An unidentified US consulate spokesperson said that while they do not generally comment on private diplomatic meetings, they will not hesitate to express publicly or privately the deep concern of the US over the erosion of Hong Kong’s autonomy.

In his address to the US Centre for Strategic and International Studies, Mr May also cited a decision by China’s legislature that lets Hong Kong’s executive branch decide whether foreign lawyers can be involved in national security cases in the city.

The decision was made after the city’s top court allowed pro-democracy publisher Jimmy Lai to hire a British lawyer to represent him as he fights collusion charges.

Mr Liu’s office accused Mr May of slandering the rule of law and freedom in Hong Kong when he questioned the legal decision made in Beijing and other changes in Hong Kong’s governance.

Hong Kong was a British colony from 1841-1941 after which it was occupied by the Japanese during World War II until 1945. The British assumed control after the war and handed the colony back to China in 1997.

Hong Kong is among a raft of issues that have set Beijing-Washington relations to their lowest level in years, including trade, Taiwan and unsubstantiated allegations that a wayward weather balloon over the US was on a spying mission for the Chinese.