President Donald Trump says the US is taking action to revoke Hong Kong's special trading status, saying China is in "plain violation" of treaty obligations regarding the territory's autonomy.
"They broke their word to the world on ensuring the autonomy of Hong Kong," Trump said from the White House, while blaming China for a "cover up" of the coronavirus outbreak.
"Therefore I am directing my administration to begin the process of eliminating policy exemptions that give Hong Kong different and special treatment," Mr Trump said today.
Mr Trump added this will impact the "full range" of agreements with Hong Kong including extradition, export controls, dual-use technology and Hong Kong's treatment as a separate customs territory from mainland China.
China's ceremonial legislature this week endorsed a national security law for Hong Kong.
The National People's Congress approved the bill as it wrapped up an annual session that was held under intensive anti-coronavirus controls.
The Hong Kong security law will alter the territory's mini-constitution, or Basic Law, to require its government to enforce measures to be decided later by Chinese leaders.
Activists in Hong Kong have complained the law will undermine civil liberties and might be used to suppress political activity.