Trump suspended U.S. contributions to the WHO last month, accusing it of promoting China’s “disinformation” about the coronavirus outbreak, although WHO officials denied the accusation and China said it was transparent and open.
"If the WHO does not commit to major substantive improvements within the next 30 days, I will make my temporary freeze of United States funding to the WHO permanent and reconsider our membership," Trump told its chief, Tedros Adhanom Ghebreyesus, in a letter posted on Twitter.
Earlier, Trump said the WHO had “done a very sad job” in its handling of the virus and he would make a decision soon on U.S. funding.
In his letter, Trump said the only way forward for the body was if it could demonstrate independence from China, adding that his administration had already started reform discussions with Tedros.
On Monday, the WHO said an independent review of the global virus response would begin as soon as possible and it had received backing and a hefty pledge of funds from China, in the spotlight as the origin of the pandemic.
More than 4.75 million people have been reported to have been infected globally and 314,414 have died.
The United States contributed more than $400 million to the WHO in 2019, or roughly 15% of the organisation’s budget. And this year, Washington has already paid the WHO about $58 million, senior Trump administration officials said last month, half of what it is required to pay for 2020 - known as an assessed contribution.