President Joe Biden’s call for a 90-day sprint to understand the origins of the coronavirus pandemic came after intelligence officials told the White House they had a raft of still-unexamined evidence that required additional computer analysis that might shed light on the mystery, according to senior administration officials.

The officials declined to describe the new evidence. But the revelation that they are hoping to apply an extraordinary amount of computer power to the question of whether the virus accidentally leaked from a Chinese laboratory suggests that the government may not have exhausted its databases of Chinese communications, the movement of lab workers and the pattern of the outbreak of the disease around the city of Wuhan.

In addition to marshaling scientific resources, Biden’s push is intended to prod American allies and intelligence agencies to mine existing information — such as intercepts, witnesses and biological evidence — as well as hunt for new intelligence to determine whether the Chinese government covered up an accidental leak.

Biden on Thursday committed to making the results of the review public, but he added a caveat: “unless there’s something I’m unaware of.”

His call for the study has both domestic and international political ramifications. It prompted his critics to argue that the president had dismissed the possibility that the lab was the origin until the Chinese government this week rejected allowing further investigation by the World Health Organization. And, administration officials said, the White House hopes U.S. allies will contribute more vigorously to a serious exploration of a theory that, until now, they considered at best unlikely, and at worst a conspiracy theory.

The effort to glean evidence from intercepted communications within China, a notoriously hard target to penetrate, has yielded little. Current and former intelligence officials say they strongly doubt anyone will find an email or a text message or a document that shows evidence of a lab accident.

One allied nation passed on information that three workers in the Wuhan virological laboratory were hospitalized with serious flu-like symptoms in the fall of 2019. The information about the sickened workers is considered important, but officials cautioned that it did not constitute evidence that they caught the virus at the laboratory — they may have brought it there.

The White House is hoping that allies and partners can tap their networks of human sources to find additional information about what happened inside the laboratory. While the United States has been rebuilding its own sources in China, it has still not fully recovered from the elimination of its network inside the country a decade ago. As a result, having allies press their informants about what went on inside the Wuhan Institute of Virology will be a key part of the intelligence push ahead.

The inquiry has not reached a dead end, a senior Biden administration official said. Officials would not describe the kind of computational analysis they want to do.

Administration and intelligence officials say it will be as much the work of scientists as spies in trying to unravel how the pandemic was unleashed. The Biden administration has been working to improve its scientific expertise on the National Intelligence Council. Senior officials have told the spy agencies that their science-oriented divisions, which have been working on the issue for months, will play a prominent role in the revitalized inquiry.

The new inquiry will also tap the national labs and other scientific resources of the federal government that previously have not been directly involved in the intelligence effort, the senior administration official said.

Biden’s announcement that he will require a report from the intelligence community had elements of showmanship.

In terms of domestic politics, he is trying to take the initiative on an issue Republicans have long focused on. Sen. Tom Cotton of Arkansas, who has long argued the coronavirus could have emerged accidentally from the Wuhan lab, said Biden’s order was “better late than never, but far from adequate.”

And on an international front, Biden called out Chinese recalcitrance to cooperate on investigations both to pressure Beijing to reverse course but also to push allies to focus their own intelligence efforts on examining the theory that the coronavirus might have accidentally leaked from the lab.

Like scientists and the broader public, the intelligence community remains uncertain about the origins of the coronavirus. No definitive intelligence has emerged, and some current and former officials expressed caution that much more can be gathered in 90 days. While the Office of the Director of National Intelligence will deliver a report before summer’s end, the inquiry will most likely have to be extended.

On Wednesday, Gen. Mark Milley, chairman of the Joint Chiefs of Staff, told reporters he had not seen any conclusive evidence about what was the cause of the pandemic, but supported the effort to look deeper. “The amount of death, pain and suffering that was experienced in this pandemic is huge,” he said. “We need to know the origin, how this happened.”

The effort to uncover the origins of the coronavirus began more than a year ago, during the Trump administration. But some officials were wary of President Donald Trump’s motives, arguing that his interest in the origins of the pandemic was either to deflect blame from his administration’s handling of it or to punish China.

Current officials say the central goal of the new intelligence push is to improve preparations for future pandemics. As a result, Biden’s message this week was calibrated to leave open the possibility of future cooperation with China.

The White House’s frustration with China has risen after its announcement this week that Beijing would not participate in additional investigations by the WHO. A Biden administration official said if the new inquiry failed to yield an answer, it would be because China had not been transparent.

But the administration is not trying to isolate China and is instead attempting to walk a careful line between pressuring Beijing to cooperate and demonstrating that in its absence, the United States will intensify its own investigation.

Administration officials also believe that the new inquiry and Chinese obstruction of the WHO will create the opportunity for stepped-up intelligence cooperation with allies.

Allies have been providing information since the beginning of the pandemic, one official said. But some, including British intelligence services, have been skeptical of the lab-leak theory. Others, including Australia, have been more open to it.

As members of the so-called Five Eyes partnership, Britain and Australia already broadly share intelligence with the United States. But the new intelligence review, along with growing frustration with China’s failure to cooperate with the WHO, could prod allies to focus more on the question of the lab leak.

A British official declined to comment. A request for comment from the Australian government was not immediately returned.

In his announcement Wednesday, Biden said two intelligence agencies believed the virus most likely occurred naturally, while at least one other favored the theory that it leaked accidentally from a lab in China. None had high confidence in their assessments, Biden noted.

In a statement Thursday, Amanda Schoch, spokesperson for the Office of the Director of National Intelligence, said the intelligence agencies had come together around the two likely scenarios, but there were no high-confidence assessments of the virus’s origins.

“The U.S. intelligence community does not know exactly where, when or how the COVID-19 virus was transmitted initially,” Schoch said.

While 18 agencies make up the intelligence community, only a handful have been major players in assessing the likely origins of the virus. Most of the broader intelligence community, including the CIA and the Defense Intelligence Agency, believe there is not yet sufficient information to draw a conclusion, even with low confidence, about the origins.

The intelligence community “continues to examine all available evidence, consider different perspectives, and aggressively collect and analyze new information to identify the virus’s origins,” Schoch said.

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