The chief of the World Health Organization (WHO) on Wednesday warned against politicizing COVID-19 just a day after US President Donald Trump accused the organization of making wrong calls and threatened to put US funding to it on hold.

At the daily novel coronavirus briefing at the White House on Tuesday, Trump said "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."

He accused the WHO of not having been aggressive enough in combating the virus, saying, "They called it wrong. They call it wrong. They really, they missed the call."

The US president also accused the WHO of being "very China centric".

WHO Director-General Tedros Adhanom Ghebreyesus did not respond directly to requests to comment on Trump's words, but warned that no person should politicize the virus.

"If you want to be exploited (by the virus), and if you want to have many more body bags, then you do it," he said, without mentioning Trump by name.

"Please quarantine politicizing COVID," he added.

Tedros said there is no need to use COVID-19 to score political points. "You have many other ways to prove yourself," he told a virtual news conference, from Geneva.

Trump's comments on Tuesday have widely been viewed as him playing the blame game, after the number of cases and deaths in the US climbed dramatically and public disapproval of his handling of the coronavirus crisis has grown.

Tedros also called for unity and solidarity at a global level.

"Now the United States and China should come together to fight it. And the rest of the G20 should come together to fight it. And the rest of the world should come together to fight it," he said, adding that unity is the only option for defeating the virus.

He reiterated just how dangerous the virus is, with the contagious element of flu and the fatal element of SARS. "We will have many body bags in front of us if we don't behave," he said.

The WHO chief revealed that he has received many personal attacks, including death threats, in the past three months. One persistent racist attack against him came from Taiwan.

He said he "does not care" about the personal attacks, but said that when the whole African community is insulted, he won't tolerate it.

"Why would I care about being attacked while people are dying?" he said. "My focus is saving lives."

Tedros said the WHO will do everything it can to defeat the virus, but admitted that in the process it may also make mistakes.

The WHO chief also warned the news media of not adding fuel to the fire and not politicizing COVID-19.

He dismissed the comment that WHO is "China centric", saying, "We are close to every nation. We are color blind".

Tedros thanked the US for its generous support to the WHO over the years, and said he believes the US will continue to contribute its share because it has a bipartisan position on supporting global health.

He expressed that with unity and solidarity at national and global levels, resources will not be a problem.

Bruce Aylward, senior advisor to Tedros, defended the WHO's relationship with China in another news briefing on Wednesday. He said that its work with China was important to understand the outbreak, which began in Wuhan in December.

"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," said Aylward, who led a WHO-China Joint Mission, in China in February.

"This is what we did with every other hard-hit country like Spain, and had nothing to do with China specifically," he was quoted as saying in a Reuters report.

Nicholas Burns, a former US under-secretary of state for political affairs in the George W. Bush administration, questioned the logic of Trump's threat to the WHO.

"Trump now wants to cut funding for the World Health Organization? In the middle of the pandemic? Insanity," Burns wrote in a tweet on Tuesday.