WASHINGTON — President Donald Trump said he is taking a malaria drug to protect against the coronavirus, despite warnings from his own government that it should only be administered for COVID-19 in a hospital or research setting due to potentially fatal side effects.

Trump told reporters Monday he has been taking the drug, hydroxychloroquine, and a zinc supplement daily “for about a week and a half now.”

Trump has spent weeks pushing hydroxychloroquine as a potential cure or prophylaxis for COVID-19 against the cautionary advice of many of his administration’s top medical professionals. The drug has the potential to cause significant side effects in some patients and has not been shown to combat the new coronavirus.

Later, in a move that could have far-reaching medical impact during the pandemic, Trump tweeted a letter he had sent to the World Health Organization threatening to permanently drop U.S. funding unless WHO commits to “substantive improvements” over the next 30 days. The U.S. provides $450 million a year to the organization.

Trump has accused WHO of giving “bad advice, terrible advice” and favoring China. In the letter to WHO Director-General Tedros Adhanom Ghebreyesus, Trump said “the only way forward” is if WHO “can actually demonstrate independence from China.” Before releasing the letter Trump had said he was considering cutting U.S. funding by more than 90 percent.

WHO announced Monday that it would launch an independent probe into how it managed the international response to the coronavirus, as most of its member states have requested. It did not commit to investigating the origins of the virus, another point of contention between Trump and China.

At the White House, Trump said his doctor did not recommend hydroxychloroquine to him, but that he requested it from the White House physician.

“I started taking it, because I think it’s good,” Trump said. “I’ve heard a lot of good stories.”

The White House physician, Dr. Sean Conley, said in a statement released through the White House press office that, after “numerous discussions” with Trump about the evidence for and against using hydroxychloroquine, “we concluded the potential benefit from treatment outweighed the relative risks.”

The Food and Drug Administration warned health professionals last month that the drug should not be used to treat COVID-19 outside of hospital or research settings, due to sometimes fatal side effects. Regulators issued the alert for the drug, which can also be used to treat lupus and arthritis, after receiving reports of heart rhythm problems, including deaths, from poison control centers and other health providers.

Trump dismissed reports of side effects, saying, “All I can tell you is, so far I seem to be OK.”

House Speaker Nancy Pelosi told CNN, “He’s our president, and I would rather he not be taking something that has not been approved by the scientists, especially in his age group and his, shall we say, weight group ... morbidly obese, they say.”

Trump is 73. At his last full checkup in February 2019 he passed the official threshold for being considered obese, with a Body Mass Index of 30.4. According to the Centers for Disease Control and Prevention, a BMI of 40 or above is considered “severe” obesity, which some also call “morbid” obesity.

Senate Democratic leader Chuck Schumer called Trump’s remarks “dangerous.”

“Maybe he’s really not taking it because the president lies about things characteristically,” Schumer said on MSNBC. He added: “I don’t know whether he is taking it or not. I know him saying he is taking it, whether he is or not, is reckless, reckless, reckless.”

At least two White House staffers tested positive for COVID-19 earlier this month, sparking concerns about the steps taken by the administration to protect the president and sending Vice President Mike Pence and other officials into varying forms of self-isolation.

The White House has since mandated that those in the West Wing wear face coverings and has introduced daily testing for the virus for the president, vice president and those they come in close contact with. Trump says he continues to test negative for the coronavirus.