President Donald Trump threatened to permanently cut U.S. funding to the World Health Organization and "reconsider" membership of the global health body if the WHO does not adopt "major substantive improvements" within 30 days.

Trump's demands, made in a letter Tuesday to WHO Director-General Tedros Adhanom Ghebreyesus, are an escalation of his attacks on the organization. He accused the WHO of "repeated missteps" during the coronavirus pandemic and demanded it "demonstrate independence" from China.

"My administration has already started discussions with you on how to reform the organization. But action is needed quickly. We do not have time to waste," Trump wrote in his ultimatum, which comes about a month after he froze WHO funding pending a formal investigation into the international health body and its coronavirus response.

The letter lists Trump's allegations that the United Nations agency missed warning signs of the virus' spread and then blithely accepted China's lack of transparency over the outbreak, such as whether the coronavirus could be transmitted between humans. The WHO initially circulated preliminary Chinese claims that there was no clear evidence of human-to-human transmission of the coronavirus.  

In his letter, Trump did not outline specific actions the WHO needs to take to satisfy his demands. On Monday, Trump called the U.N.'s health body a "puppet of China."

Zhao Lijian, a spokesman for China's foreign ministry, said Trump's letter was "smearing and slandering China’s efforts in epidemic prevention and to shift responsibility in its own incompetence in handling the epidemic."

The WHO said in a statement it was "considering the contents" of Trump's letter but otherwise it had no further comment. 

The organization has previously disputed claims from the Trump administration that it acted too slowly in sounding the alarm over coronavirus. Public health experts have long warned the agency is overly bureaucratic and in need of reform. Little evidence has emerged to substantiate accusations from Trump administration officials that the WHO deliberately acted in concert with China to obfuscate what it knew about the outbreak. 

On Monday, Ghebreyesus said he would launch an independent evaluation of the WHO’s coronavirus response "at the earliest appropriate moment." And China's leader Xi Jinping said he would support an independent investigation into the pandemic, though it remains unclear whether any such review would probe the origins of the virus. Trump has floated theories, without giving evidence, that the coronavirus escaped from a lab in Wuhan, China, where the virus first emerged late last year.    

The U.S. is the WHO's biggest donor. It paid $400 million to the WHO for 2018-2019, according to the organization's website. That money represents about 15% of the WHO's budget. When Trump said last month that he would temporarily freeze WHO spending, he said he would "channel" the money into other areas to combat the coronavirus outbreak. He has not provided specifics on that pledge.  

Among the other accusations made in Trump's letter: 

He suggested that the WHO, bowing to pressure from China, delayed an emergency declaration connected to the outbreak. (There is no evidence for this claim.) He highlighted the global health body praise of China's government for its "transparency" with respect to the coronavirus, setting a "new standard for outbreak control." (True. The WHO has gone on record stating it believes China has done a good job fighting the coronavirus.)  Trump accused the WHO of  "inexplicably" opposing Trump's closure of the U.S. border and travel ban from China. (False. The WHO has for years consistently argued against closing borders and travel bans during pandemics. It has not publicly questioned Trump's decision. The WHO believes such actions can exacerbate the spread of infectious disease.) He said the agency has failed to publicly address accusations of "China's racially discriminatory actions" in China against African nationals. (True.)  Trump suggested the Lancet, a British medical journal, published a report in early December about a virus spreading in Wuhan. (False, according to the Lancet. Its editor said the first reports it published were from Chinese scientists on Jan 24, 2020.)

This is the letter sent to Dr. Tedros of the World Health Organization. It is self-explanatory!

— Donald J. Trump (@realDonaldTrump)May 19, 2020

Trump's announcement comes as the WHO is holding its annual general assembly online. It ends Tuesday. The forum has been dominated by many of its 194 members pushing for a review over how the organization responded to the outbreak. 

In an interview with the BBC, former Australian Prime Minister Kevin Rudd said it would be "grossly irresponsible in international humanitarian terms" for the U.S. to permanently withdraw its funding for the WHO because of its potential impact on poor countries around the world where the virus has yet to have its full impact.

"The WHO goes in and advises and/or provides direct material help with the setting up of health systems to deal with the crisis on the ground," he said.