It is not clear whether the President can pull the US out of the organisation and withdraw funding without Congress approval. When Trump first threatened to withdraw,Democratic lawmakers argued that doing so would be illegal and vowed to push back.
Democratic Senator Robert Menendez tweeted on Tuesday that Congress had received notification of the withdrawal:
"Congress received notification that POTUS officially withdrew the US from the @WHO in the midst of a pandemic.
"To call Trump's response to COVID chaotic&incoherent doesn't do it justice. This won't protect American lives or interests – it leaves Americans sick&America alone."
The decision to withdraw in the middle of a pandemic puts the US at odds with traditional allies.
"We have a lot of allies on improving WHO,but we have no allies on abandoning WHO,"said Jimmy Kolker,a former US ambassador who served as assistant secretary for global affairs at the Department of Health and Human Services until 2017.