China passed a security law that gives Beijing sweeping powers over Hong Kong Tuesday (June 30) morning.
The territory's Cable TV, citing an unidentified source, said the law was passed unanimously by China's parliament.
It sets the stage for the most radical changes to the former British colony since it was handed back to China in 1997.
The law is a response to last year's often-violent pro-democracy protests in the city.
A draft of the law had not yet been published, but Beijing says it aims to tackle subversion, terrorism, separatism and collusion with foreign forces.
There are reports that the heaviest penalty under the law would be life imprisonment.
Hong Kong's leader Carrie Lam spoke shortly after news broke, but refused to comment.
The law puts China on a collision course with the U.S., UK and other Western governments.
They say it chips away at the high degree of autonomy Hong Kong was granted at the handover.
Beijing says the law will target only a small group of troublemakers, and will not affect rights and freedoms, nor investor interests..
But on Monday Washington said it would end Hong Kong's special status under U.S. law.
That will stop defense exports to the city and restrict its access to high tech products.
Secretary of State Mike Pompeo said, the the US was left with no other choice and quote:
"The Chinese Communist Party's decision to eviscerate Hong Kong's freedoms has forced the Trump administration to re-evaluate its policies toward the territory."
On Tuesday, Carrie Lam fired back, saying: "Sanctions will not scare us, we also are mentally prepared, and if necessary the country will take responsive action."
It is still unclear which specific activities are to be made illegal, or what punishment they carry.
However, Chinese state media already unveiled parts of the law.
Judges for security cases are expected to be appointed by Carrie Lam.
The law comes into force as soon as it is officially published in Hong Kong.