U.S. President Donald Trump says he has directed a halt to U.S. payments to the World Health Organization (WHO) pending a review of its warnings about the coronavirus and China.

Trump said at a White House news conference on Tuesday the outbreak could have been contained at its source and spared lives had the UN health agency done a better job investigating reports coming out of China.

He said the world depends on the WHO to work with countries to make sure accurate information about health threats are shared in a timely manner.

"The WHO failed in its basic duty and must be held accountable," Trump said at the briefing. He said the U.S. would be reviewing the WHO's actions to stop the virus before making any decision on resuming aid.

There was no immediate comment from the Geneva-based organization, but when asked about possible U.S. funding cuts during a regular UN briefing earlier Tuesday, WHO spokeswoman Margaret Harris responded, "Regardless of any issues, our work will go on."

Trump said the U.S. will continue to engage with the WHO in pursuit of "meaningful reforms."

"We're doing a very thorough investigation as we speak," he told reporters, saying it would take about 60 to 90 days.

"[The WHO] is very China-centric," he said, adding, it's "not right."

The United States contributed nearly $900 million US to the WHO's budget for 2018-19, according to information on the agency's website. That represents one-fifth of its total $4.4 billion budget for those years. The U.S. gave nearly three-fourths of the funds in "specified voluntary contributions" and the rest in "assessed" funding as part of Washington's commitment to UN institutions.

A more detailed WHO budget document provided by the U.S. mission in Geneva showed that in 2019, the U.S. provided $452 million, including nearly $119 million in assessed funding. In its most recent budget proposal from February, the Trump administration called for slashing the U.S. assessed funding contribution to the WHO to $57.9 million.

Last week, the head of the WHO gave a strident defence of his agency's handling of the pandemic after Trump threatened to halt WHO funding.

Tedros Adhanom Ghebreyesus, director general of the World Health Organization, called for Trump last week to end the politicization of the global health crisis. (Denis Balibouse/Reuters)

Director general Tedros Adhanom Ghebreyesus repeatedly called for unity and a halt to "politicization" of the global health crisis.

Tedros, a former foreign minister of Ethiopia, also rejected Trump's suggestion that the WHO was "China-centric," saying: "We are close to every nation, we are colour-blind."

Trump himself showed deference to China at the beginning stages of the outbreak.

"China has been working very hard to contain the Coronavirus," he tweeted on Jan. 24. "The United States greatly appreciates their efforts and transparency. It will all work out well. In particular, on behalf of the American People, I want to thank President Xi!"