Updated at 3:43 p.m. ET
The United States is rescinding a number of special considerations for Hong Kong in retaliation for what Washington calls a naked power grab by China's central government.
President Trump announced a suite of changes Friday in what had been billed as a press conference but which turned out to be an on-camera statement, after which he took no questions.
He focused instead on his intent to revoke Hong Kong's special customs status, impose some sanctions on officials in the mainland and Hong Kong governments, and take other steps.
The precise details or their implications weren't immediately clear. For example, Trump said he was directing a study of the "differing practices" involved with Chinese and American companies in financial markets, arguing that U.S. investors deserved what he called "fair" treatment.
It could have implications for Chinese companies or banks and Hong Kong's status as a major Asian financial center, although there was no detail about when Trump might get the "study" or what it could contemplate.
President excoriates Beijing
Sino-American relations have been on a low ebb for years but may have hit a recent nadir with Trump's remarks Friday.
Trump blamed China's communist government for the global coronavirus pandemic, which has taken 100,000 American lives and more broadly sent shock waves around the world.
"The death and destruction caused by this is incalculable," he said.
The White House argues that China's repression and mendacity meant the world was unprepared for the lethality and contagiousness of the virus, which originated in Wuhan, capital of Hubei province.
The president has gone back and forth about how strongly he blames Beijing. Earlier in the pandemic, he alluded to the coronavirus as "the Chinese virus" before softening his language and then resuming direct condemnation of Chinese authorities.
Trump put the pandemic into the context of years of what he called bad practices and mistreatment by China, including its theft of hundreds of billions of dollars' worth of American intellectual property. He took credit for standing up for the United States.
Trump and aides also blame the World Health Organization for the pandemic, and the president followed earlier condemnations and threats Friday by saying that the U.S. would sever its ties with the agency.
Washington will divert roughly $500 million per year it has paid to WHO to other global health organizations, Trump said. Those details weren't clear either, including which groups or how quickly.
The United States has been the single biggest funder of WHO, and the breach announced by Trump raises questions about how it may be able to move forward.
Anger over Hong Kong
Trump and Secretary of State Mike Pompeo have faulted the Chinese government after it asserted more control over Hong Kong's governance despite earlier commitments to maintain "two systems" — one for the mainland and one for Hong Kong.
Hong Kong was a British colony until the late 1990s when London agreed to turn over control to Beijing with the proviso that it enjoy more autonomy and more freedoms, which residents had come to expect under British rule.
Beijing agreed, but critics in Hong Kong and elsewhere have said the central government has been steadily eroding the city's liberties.
Last year, protesters shut down Hong Kong for weeks with demonstrations against a proposed law that would have permitted citizens there to have been sent to the mainland for trial.
Activists said they feared the mainland's weak protections in law would open up everyone in Hong Kong to arbitrary Chinese punishment and further weaken the special status Hong Kong was supposed to enjoy.
Trump was mostly quiet then, but his tune has changed sharply since the coronavirus pandemic — which the president blames on the Chinese government.
Pompeo has made a formal proclamation to Congress that the United States can no longer consider Hong Kong independent from China, raising the prospect of changes in its diplomatic relationship with Washington.
One of the big unresolved questions in the contretemps between Washington and Beijing is over Taiwan, the independent Republic of China considered a breakaway province by the central government on the mainland.
The United States has maintained close ties with Taiwan and has some legal obligations to defend it if attacked by China. But that relationship hasn't been tested by a major military crisis, and until now, the mainland government hasn't been as assertive about some of its key claims as it has been with Hong Kong.
Trump condemned China's territorial claims broadly Friday, but he did not specify what his position would be on a major dispute over Taiwan.