The Trump Administration has formally notified the United Nations of its withdrawal from the World Health Organisation.
The pullout won't take effect until next year, meaning it could be rescinded under a new administration or if circumstances change.
The withdrawal notification follows United States President Donald Trump's decision in late May to terminate US participation in the WHO, which he has criticised for its response to the coronavirus pandemic and accused of bowing to Chinese influence. The move was immediately assailed by health officials and critics of the administration.
The withdrawal notice was sent to UN Secretary-General Antonio Guterres yesterday and will take effect in a year, on July 6, 2021, the State Department and the United Nations said today.
Guterres, in his capacity as depositary of the 1946 WHO constitution, "is in the process of verifying with the World Health Organisation whether all the conditions for such withdrawal are met," his spokesman, Stephane Dujarric, said.
Under the terms of the withdrawal, the US must meet its financial obligations to the WHO before it can be finalised. The US, which is the agency's largest donor and provides it with more than US$400 million per year, currently owes the WHO some US$200 million in current and past dues.
In late May, less than two weeks after warning the WHO that it had 30 days to reform or lose US support, Trump announced his Administration was leaving the organisation due to what he said was its inadequate response to the initial outbreak of the coronavirus in China's Wuhan province late last year.
The President said in a White House announcement that Chinese officials "ignored" their reporting obligations to the WHO and pressured the organisation to mislead the public about an outbreak that has now killed more than 130,000 Americans.
The withdrawal notification was widely denounced as misguided, certain to undermine an important institution that is leading vaccine development efforts and drug trials to address the Covid-19 outbreak.
"The Administration's move to formally withdraw from WHO amid the greatest public health crisis that Americans and the world have faced in a century is short-sighted, unnecessary, and unequivocally dangerous," said UN Foundation President Elizabeth Cousens.
"WHO is the only body capable of leading and coordinating the global response to Covid-19. Terminating the US relationship would undermine the global effort to beat this virus — putting all of us at risk."
The One Campaign, which supports international health projects, called it an "astounding action" that jeopardises global health.
"Withdrawing from the World Health Organisation amidst an unprecedented global pandemic is an astounding action that puts the safety of all Americans and the world at risk. The US should use its influence to strengthen and reform the WHO, not abandon it at a time when the world needs it most," One president Gayle Smith said.