Coronavirus Live Updates: U.S. and Global News

“The United States’ notice of withdrawal, effective July 6, 2021, has been submitted to the U.N. secretary general, who is the depository for the W.H.O.,” said a senior administration official.

By law, the United States must give the organization a year’s notice if it intends to withdraw, and meet all the current financial obligations in the current year.

Mr. Trump, whose response to the pandemic has drawn criticism, first announced that he planned to halt funding to the W.H.O. in April, claiming that the organization had made a series of mistakes as it battled the coronavirus.

His move to withdraw drew immediate criticism. Senator Lamar Alexander of Tennessee, a Republican who is the chairman of the Senate’s health committee, said that he disagreed with the president’s decision.

“Withdrawing U.S. membership could, among other things, interfere with clinical trials that are essential to the development of vaccines, which citizens of the United States as well as others in the world need,” he said in a statement. “And withdrawing could make it harder to work with other countries to stop viruses before they get to the United States.”

The nation cannot withdraw until next year, after the presidential election. Former Vice President Joseph R. Biden Jr., the presumptive Democratic nominee, said on Twitter that he would rejoin the W.H.O. “on my first day as President.”

The president of the United Nations Foundation, Elizabeth Cousens, said in a statement that the administration’s “move to formally withdraw from the W.H.O. amid the greatest public health crisis that Americans and the world have faced in a century is shortsighted, unnecessary, and unequivocally dangerous.”