The White House on Thursday called China’s rejection of a second phase of the World Health Organization's (WHO) investigation into the origins of the coronavirus “irresponsible” and “dangerous.”

“We are deeply disappointed. Their position is irresponsible and frankly dangerous,” White House press secretary Jen Psaki told reporters when asked about Beijing’s rejection of the investigation, which would examine the possibility the virus emerged from a laboratory.

“Alongside other member states around the world, we continue to call for China to provide the needed access to data and samples and this is critical so we can understand, to prevent the next pandemic. This is about saving lives in the future, and it’s not a time to be stonewalling,” she added.

Psaki reiterated the Biden administration’s support for a second phase of the investigation that is “scientific, transparent, expert-led and free from interference.”

Zeng Yixin, the vice minister of China’s National Health Commission, said at a press conference earlier Thursday that China would not participate in phase two of the investigation. Zeng said he was “rather taken aback” that the study would investigate further the possibility that the virus emerged from a lab in Wuhan.

“It is impossible for us to accept such an origin-tracing plan,” he said, according to The Associated Press.

A WHO-led report issued in March found that COVID-19 most likely transferred from animals to humans and described the lab-leak scenario as "extremely unlikely." However, WHO Director-General Tedros Adhanom Ghebreyesus said at the time that the United Nations health body was not ruling out any theories. The initial report was written jointly with Chinese scientists.

Biden in May ordered U.S. intelligence agencies to “redouble their efforts” to come to a definitive conclusion on the disease’s origins, after new reports pointed to circumstantial evidence that it could have emerged from a lab.

The U.S. has pressured China to provide more access to data and other information so that the global community can get to the bottom of the source of COVID-19, which was first discovered in Wuhan in 2019.

The Group of Seven leaders called for a renewed and “transparent” investigation into the origins of the coronavirus following a summit last month.

The pressure has not had an apparent impact on China's willingness to cooperate, however. 

Asked Thursday whether there would be consequences on China for its rejection of the independent study, Psaki declined to answer but said the U.S. approach to Beijing is coordinated with allies.