The World Health Organization, or WHO, said on Wednesday it regrets the US decision to halt funding to the organization and it was assessing the possible impact.

US President Donald Trump announced on Tuesday that he is halting funding to the WHO while his administration reviews its handling of the novel coronavirus crisis. He has accused the WHO of not making correct and timely calls about the threat, and of it being "China centric".

"We regret the decision of the president of the United States to order a halt in funding to the WHO," WHO Director-General Tedros Adhanom Ghebreyesus told a virtual news conference from Geneva.

He praised the US for being a longstanding generous friend to the WHO, saying "we hope it will continue to be so".

Tedros said that the WHO is reviewing the impact on its work of any withdrawal of US funding and will work with its partners to fill any financial gaps it faces to ensure its work continues uninterrupted.

The US is the largest fund contributor to the WHO, by providing about $400 million a year, but some of its payments are in arrears.

The WHO chief emphasized that his organization is not only fighting COVID-19, but also working to address a wide range of diseases and conditions such as polio, measles, malaria, Ebola, HIV, tuberculosis, malnutrition, cancer, diabetes, mental health. He expressed that the WHO also works with countries to strengthen health systems and improve access to life-saving health service.

"Our commitment to public health, science and to serving all the people of the world without fear or favor remains absolute," Tedros said, adding that the WHO's mission and mandate are to work with all nations equally, without regard to the size of their populations or economies.

He reiterated that COVID-19 does not discriminate between rich nations and poor nations, large nations and small nations, nor it discriminates between nationalities, ethnicities or ideologies.

"When we are divided, the coronavirus exploits the cracks between us," Tedros said.

Trump's announcement on Tuesday has been largely interpreted as an effort to deflect attention from the sharp criticism he faced at home for his poor handling of the pandemic crisis.

Josep Borrell, the European Union foreign policy chief, said on Wednesday that he deeply regrets the US decision to suspend funding to the WHO.

"There is no reason justifying this move at a moment when their efforts are needed more than ever to help contain and mitigate the coronavirus pandemic. Only by joining forces can we overcome this crisis that knows no borders," he tweeted.

Microsoft co-founder Bill Gates, a major supporter for the global public health cause, said that halting funding for WHO during a world health crisis is "as dangerous as it sounds".

"Their work is slowing the spread of COVID-19 and if that work is stopped no other organization can replace them. The world needs @WHO now more than ever," Gates tweeted on Wednesday.

Richard Horton, editor of The Lancet, described Trump's decision as "a crime against humanity".

"Every scientist, every health worker, every citizen must resist and rebel against this appalling betrayal of global solidarity," he wrote in a tweet, immediately after Trump's announcement.