President Donald Trump said Friday that the United States will restrict Chinese students and start reversing Hong Kong's special status in customs and other areas, as Beijing imposes a controversial security law.
Trump said the Chinese government has been "diminishing the city's longstanding and very proud status."
"This is a tragedy for the people of Hong Kong, the people of China, and indeed the people of the world," Trump told reporters.
Secretary of State Mike Pompeo on Wednesday told Congress that the Trump administration would no longer consider Hong Kong to be separate under US law but did not spell out the consequences.
Trump also was light on specifics but said: "I am directing my administration to begin the process of eliminating policy that gives Hong Kong different and special treatment."
"This will affect the full range of agreements, from our extradition treaty to our export controls on dual-use technologies and more, with few exceptions," he said.
Trump also said he would restrict the entry of some graduate students from China -- the largest source of foreigners to US universities -- but did not immediately give numbers.
"For years, the government of China has conducted elicit espionage to steal our industrial secrets, of which there are many," Trump said.
"Today I will issue a proclamation to better secure our nation's vital university research and to suspend the entry of certain foreign nationals from China who we have identified as potential security risks."