WASHINGTON, May 20 (Xinhua) -- Many experts have blasted U.S. President Donald Trump's letter to World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus.

In the letter, a copy of which was published by Trump on Twitter Monday, the president threatened that the United States will permanently cut off its funding to the WHO if the latter does not commit to what he called "substantive improvements within the next 30 days."

Lawrence Gostin, a professor of global health law and director of the O'Neill Institute for National and Global Health Law at Georgetown University, tweeted on Tuesday that the letter to Tedros "is like a bully making a threat" and "factually it's wrong."

Gostin, also the director of the WHO collaborating center on national and global health law, questioned Trump's ability to carry out the threats, arguing that the U.S. "Congress won't support leaving" the organization.

Trump announced in mid-April that his administration would halt U.S. funding to the WHO, a roundly-criticized move that many experts have said was trying to shift blames and would be counterproductive to addressing the public health crisis.

The United States alone has reported more than 1.5 million infections and over 90,000 deaths, according to a count by Johns Hopkins University. Both figures are far higher than those in any other country or region.

Max Boot, a senior fellow for national security studies at the Council on Foreign Relations, a U.S. think tank, said that "it is hard to imagine a more unconvincing and counterproductive document" in an op-ed published on The Washington Post on Tuesday in response to Trump's letter.

"Threatening to leave the WHO during a global health crisis is the geopolitical equivalent of injecting Clorox as a coronavirus remedy," Boot wrote. "The United States chose to go it alone and fell hopelessly behind in fighting the pandemic. That's Trump's fault, not the WHO's."

The Lancet, a leading British medical journal, rebuked Trump after he incorrectly cited research it published on the coronavirus outbreak, saying that "this statement is factually incorrect."

"The allegations levelled against WHO in President Trump's letter are serious and damaging to efforts to strengthen international cooperation to control this pandemic," the journal said in a statement.

The Trump administration has aggressively defended its handling of the public health crisis, while critics have pointed out that its leaders and officials ignored early warnings, were slow to act and tried to politicize the situation to shift blame.