Updated August 27, 2021 at 7:15 PM ET

A much anticipated U.S. intelligence report on the origins of the COVID-19 pandemic has failed to reach any firm conclusion on whether the coronavirus first found its way into humans through contact with an infected animal or that the virus somehow escaped from a lab.

Both hypotheses remain plausible, according to an unclassified summary of the report's key takeaways that was released on Friday by the Office of the Director of National Intelligence.

The intelligence community "remains divided on the most likely origin of COVID-19. All agencies assess that two hypotheses are plausible: natural exposure to an infected animal and a laboratory-associated incident," the brief summary states.

Just over three months ago, President Biden ordered intelligence agencies to undertake a detailed, systematic review of any information that had been collected and could shed light on what exactly sparked the global pandemic.

"The world deserves answers, and I will not rest until we get them," Biden said on Friday, commenting on the report. "We all must better understand how COVID-19 came to be in order to prevent further pandemics."

Biden said his administration will continue to push to learn more about the origins of the COVID-19 pandemic and criticized China for preventing international investigators from accessing what he called "critical information" about the coronavirus since the beginning of the pandemic.

The intelligence analysis is inconclusive on the origin

A separate report, released earlier this year, that was based on a World Health Organization-China investigation did not come to any solid conclusions about the origins of the virus and scientists on that trip were unable to get access to key evidence. Chinese officials have said that further efforts to uncover the source of the virus should focus on other countries and have rejected the idea that it could have leaked from a lab at the Wuhan Institute of Virology, which is in the same region where the first cluster of human cases was identified.

The new U.S. intelligence review may not have settled the fundamental question of where the virus emerged, but intelligence agencies did reach "broad agreement about several other key issues" — among them, that the coronavirus was "not developed as a biological weapon."

And despite Biden's criticism of China's refusal to share more about the early days of the pandemic, the intelligence community determined Chinese officials "did not have foreknowledge of the virus" before the initial outbreak of COVID-19.

"That itself is significant," says Robert Garry, a microbiologist at Tulane University School of Medicine, because if Chinese officials didn't know about it, then the Wuhan Institute of Virology didn't either, he said.

"It appears the needle was moved in the intelligence community more towards the natural origin," says Garry. "I think that you have to look at the scientific data that's out there. Follow the science, follow the animals."

The lack of definitive answers from the intelligence report did not necessarily come as a surprise to scientists who've been trying to track down the origins of the coronavirus.

"This is an intelligence community report, not a scientific report," says Michael Worobey, an evolutionary biologist at the University of Arizona. He would like to see the scientific and intelligence communities collaborate on the problem. "I would hope and assume that this 90-day sprint is going to turn into a nice long jog where there could be some back-and-forth."

Key clinical samples and data from the earliest COVID-19 cases still remain out-of-reach, both for scientists and intelligence agencies, as the summary of the intelligence review states. But Worobey thinks scientists will continue to make progress, even without major revelations from the intelligence community.

"I'm hopeful there will be ways to move things forward," he says. "And I'm hopeful that China will realize it's in their self-interest in some way to put to rest the question of lab leaks."

Copyright 2021 NPR. To see more, visit https://www.npr.org.