WASHINGTON — President Donald Trump has announced that he would withdraw funding from the World Health Organization, end Hong Kong's special trade status and suspend visas of Chinese graduate students suspected of conducting research on behalf of their government, escalating tensions with China that have surged during the coronavirus pandemic.

Trump has been expressing anger at the World Health Organization for weeks  over what he has portrayed as an inadequate response to the initial outbreak of the coronavirus in China's Wuhan province late last year.

The president said in a White House announcement Friday that Chinese officials "ignored" their reporting obligations to the WHO and pressured the organization to mislead the public about an outbreak that has now killed more than 100,000 Americans. 

"We have detailed the reforms that it must make and engaged with them directly, but they have refused to act," the president said. "Because they have failed to make the requested and greatly needed reforms, we will be today terminating the relationship."

The U.S. is the largest source of financial support for the WHO, and its exit is expected to significantly weaken the organization. Trump said the U.S. would be "redirecting" the money to "other worldwide and deserving urgent global public health needs," without providing specifics. 

He noted that the U.S. contributes about $450 million to the world body while China provides about $40 million.

Congressional Democrats said in April, when the president first proposed withholding money from the WHO, that it would be illegal without approval from Congress and that they would challenge it. House Speaker Nancy Pelosi on Friday called the move "an act of extraordinary senselessness."

Other critics of the administration's decision to cut funding called it misguided, saying it would undermine an important institution that is leading vaccine development efforts and drug trials to address the COVID-19 outbreak.

"Severing ties with the World Health Organization serves no logical purpose and makes finding a way out of this public health crisis dramatically more challenging," said Dr. Patrice Harris, president of the American Medical Association.

The WHO declined to comment on the announcement. Officials of the U.N. agency have not directly addressed a letter that Trump sent to the general director on May 18 warning that he would make permanent a temporary freeze on U.S. funding and reconsider U.S. membership unless it committed to "major substantive improvements within the next 30 days." 

Republican Sen. Lamar Alexander of Tennessee, chairman of the Senate health committee, also warned that the president's decision could interfere with vaccine trials and international cooperation during future outbreaks. 

"Certainly there needs to be a good, hard look at mistakes the World Health Organization might have made in connection with coronavirus, but the time to do that is after the crisis has been dealt with, not in the middle of it," said Alexander, echoing a point made by others, including the head of the United Nations.

At an event later Friday, Trump was asked about relations with China, and he repeated his earlier suspicions about how the country managed to apparently contain the virus in Wuhan while it spread to Europe and the United States. 

"Well, we're certainly not happy with what happened with respect to China," he told reporters.

Tensions over Hong Kong have increased over the past year as China has cracked down on protesters a nd sought to exert more control over the former British territory. 

Trump said the administration would begin eliminating the "full range" of agreements that had given Hong Kong a relationship with the U.S. that mainland China lacked, including exemptions from controls on certain exports. He said the State Department would begin warning U.S. citizens of the threat of surveillance and arrest when visiting the city.

"China has replaced its promised formula of one country, two systems, with one country, one system," he said. 

Secretary of State Mike Pompeo notified Congress on Wednesday that Hong Kong is no longer deserving of the preferential trade and commercial status it has enjoyed from the U.S. since it reverted to Chinese rule in 1997.

It's not yet clear what impact the decision will have on U.S. companies that operate in Hong Kong or on the city's position as Asia's major financial hub, or how China will react to the decision. 

"The downward spiral in the bilateral relationship has now reached lows not seen since the June 4, 1989, Tiananmen massacre, and there is little reason to expect things to get better soon," said Dexter Tiff Roberts, an Asia expert at the Atlantic Council, which publishes nonpartisan policy analysis.

Rep. Chris Smith, a New Jersey Republican who is a commissioner of the Congressional Executive Commission on China, praised the decision on Hong Kong as an overdue response to the government of President Xi Jinping for human rights abuses, including against religious minorities in the Xinjiang region. 

"After years of human rights admonishment and cheap rhetoric devoid of any meaningful penalties, Xi has concluded that the West is all talk, no action," Smith said. "President Trump, however, is today beginning to change that and is doing what previous presidents have failed to do."

The president also said the U.S. would be suspending entry of Chinese graduate students who are suspected of taking part in an extensive government campaign to acquire trade knowledge and academic research for the country's military and industrial development.

Allowing their continued entry to the country would be "detrimental to the interests of the United States," Trump said in an order released after the White House announcement.

Revocation of the visas has faced opposition from U.S. universities and scientific organizations that depend on tuition fees paid by Chinese students to offset other costs and fear possible reciprocal action from Beijing that could limit their access to China.

The president's order includes an exemptions for students whose work was not expected to benefit the Chinese military.

China seemed to signal in recent days that it was hoping to ease tensions. Premier Li Keqiang told reporters on Thursday that both countries stood to gain from cooperation and to lose from confrontation because their economies have become so interconnected.

"We must use our wisdom to expand common interests and manage differences and disagreements," Li said. 

Still, the country has insisted that its control of Hong Kong is an internal matter, and it has disputed that it mishandled the response to the virus.