World Health Organisation officials have denied that the body was "China-centric" and say the acute phase of a pandemic is not the time to cut funding, after US President Donald Trump said he would put contributions on hold.
The United States is the top donor to the Geneva-based body which Trump said had issued bad advice during the new coronavirus outbreak.
US contributions to WHO in 2019 exceeded $US400 million, almost double the 2nd largest member state contribution. China, in contrast, contributed $US44 million.
"The W.H.O. really blew it," Trump said in a Twitter post.
"For some reason, funded largely by the United States, yet very China centric. We will be giving that a good look. Fortunately I rejected their advice on keeping our borders open to China early on. Why did they give us such a faulty recommendation?"
Trump repeated the accusations against the UN health organisation at a White House news briefing later on Tuesday.
"They called it wrong. They really - they missed the call," the president said. "And we're going to put a hold on money spent to the WHO. We're going to put a very powerful hold on it and we're going to see."
But WHO officials defended their organisation against Trump's claims.
"We are still in the acute phase of a pandemic so now is not the time to cut back on funding," Dr Hans Kluge, WHO Regional Director for Europe, told a virtual briefing in response to a question about Trump's remarks.
Dr Bruce Aylward, senior adviser to the WHO Director-General, also defended the UN agency's relationship with China, saying its work with Beijing authorities was important to understand the outbreak which began in Wuhan.
"It was absolutely critical in the early part of this outbreak to have full access to everything possible, to get on the ground and work with the Chinese to understand this," he told reporters.
"This is what we did with every other hard hit country like Spain and had nothing to do with China specifically."
He also defended WHO recommendations to keep borders open, saying that China had worked very hard to identify and detect early cases and their contacts and ensure they did not travel in order to contain the outbreak.
On Europe, Kluge described the outbreak of coronavirus there as "very concerning" and urged governments to give "very careful consideration" before relaxing measures to control its spread.
"A dramatic rise in cases across the Atlantic skews what remains a very concerning picture in Europe," he said. "We still have a long way to go in the marathon."
Australian Associated Press