The move could aggravate China’s worsening relations with the United States, which has long criticized China over the erosion of Hong Kong’s autonomy.

President Trump said Thursday that the United States would strongly respond to any attempt by the Chinese authorities to impose a crackdown on Hong Kong. On Wednesday, Secretary of State Mike Pompeo said China’s threats to pro-democracy activists in Hong Kong could make the United States re-evaluate the special treatment the territory receives as an autonomous region under American law. China’s Foreign Ministry responded that Mr. Pompeo was blatantly interfering in internal Chinese affairs.

More broadly, a Chinese crackdown in Hong Kong could exacerbate a credibility problem for the Beijing authorities, already defending themselves from claims of negligence and cover-up in the early stages of the coronavirus pandemic, which is believed to have originated in Wuhan late last year.

Nearby Asian countries like Vietnam and Thailand already view China’s growing attempts to exert its influence in the region with suspicion.