They cited a Twitter post by the W.H.O. on Jan. 14 saying that the Chinese government had “found no clear evidence of human-to-human transmission of the novel #coronavirus” as evidence that the W.H.O. was covering up for China. And they noted that in mid-February, a top official at the W.H.O. praised the Chinese for restrictive measures they insisted had delayed the spread of the virus to other countries, saying, “Right now, the strategic and tactical approach in China is the correct one.”

“It is very China-centric,” Mr. Trump said in announcing his decision on Tuesday in the Rose Garden.

“I told that to President Xi,” he said, referring to Xi Jinping of China. “I said, ‘The World Health Organization is very China-centric.’ Meaning, whatever it is, China was always right. You can’t do that.”

Public health experts say the W.H.O. has had a mixed record since the coronavirus emerged in late December.

The health organization raised early alarms about the virus, and Dr. Tedros Adhanom Ghebreyesus, the group’s director general, held almost daily news briefings beginning in mid-January, repeating a mantra: “We have a window of opportunity to stop this virus. But that window is rapidly closing.”

But global health officials and political leaders — not just Mr. Trump — have said the organization was too willing to accept information supplied by China, which still has not provided accurate numbers on how many people were infected and died during the initial outbreak in the country.

On Wednesday, Scott Morrison, the prime minister of Australia, called it “unfathomable” that the W.H.O. had issued a statement supporting China’s decision to allow the reopening of so-called wet markets, the wildlife markets where the virus is believed to have first spread to humans. And in Japan, Taro Aso, the deputy prime minister and finance minister, recently noted that some people have started referring to the W.H.O. as the “Chinese Health Organization.”