The Covid.gov website, previously focused on promoting vaccine and testing information, now includes a full-length image of President Donald Trump and criticizes the pandemic policies implemented under former president Joe Biden.

The site also targets Anthony Fauci, Biden's former chief medical advisor, for advancing what it calls the "preferred narrative that Covid-19 originated naturally."

It presents five bullet points aimed at bolstering the lab leak theory, noting that Wuhan, the site of the first known coronavirus case, is also home to China's "foremost SARS research lab" and has a history of conducting research at "inadequate biosafety levels."

"By nearly all measures of science, if there was evidence of a natural origin it would have already surfaced. But it hasn't," the website said.

The lab-leak theory, once dismissed as a conspiracy theory, has recently gained mainstream traction in the United States.

Even as the debate remains unresolved -- scientifically and politically -- US agencies such as the Federal Bureau of Investigation and the Department of Energy have come out in support of the theory, albeit with varying levels of confidence.

Earlier this year, the Central Intelligence Agency shifted its official stance on the virus's origin, saying that it was "more likely" leaked from a Chinese lab than transmission from animals.

The assessment drew criticism from China, which said it was "extremely unlikely" Covid-19 came from a laboratory.

Beijing also urged the United States to "stop politicizing and instrumentalizing the issue of origin-tracing."

The United States and China are currently locked in a major trade war, with Washington announcing Thursday new port fees for Chinese-linked ships and increased tariffs for Chinese goods.

The revamped White House site, which apparently seeks to redefine the political narrative about Covid-19, also criticized the mask and social distancing mandates introduced at the start of the pandemic in 2020. There is also a map of Wuhan that is animated to throb.

Under a section titled "Covid-19 misinformation," it also accused public health officials under the previous administration of demonizing "alternative treatments" and colluding with social media companies to censor dissenting views about the pandemic -- a charge frequently echoed by US conservatives.

The Biden administration has previously rejected the charge that it was suppressing or censoring conservative perspectives.

The website revamp comes after layoffs began earlier this month at major US health agencies, as the Trump administration embarks on a sweeping and scientifically contested restructuring that will cut 10,000 jobs.

Health secretary Robert F. Kennedy Jr -- who has alarmed health experts with his rhetoric downplaying the importance of vaccines -- said the layoffs were part of a major reform of his department, aiming to refocus efforts on chronic disease prevention.

More than one million people died of Covid-19 and related illnesses in the United States, and millions more were lost around the world.