WASHINGTON — American intelligence agencies have not been able to determine if the coronavirus pandemic was the result of an accidental leak from a lab or if it emerged more naturally, according to declassified portions of a report to the White House released on Friday.
The nation’s spy agencies, the Office of the Director of National Intelligence said, are unlikely to reach a conclusion without more cooperation from China or new source of information.
In a statement, President Biden said the United States would continue working to understand the origins of the virus and he called on China to be more transparent about what led to the virus emerging there in late 2019 before spreading rapidly across the globe.
“We will do everything we can to trace the roots of this outbreak that has caused so much pain and death around the world, so that we can take every necessary precaution to prevent it from happening again,” Mr. Biden said. “Critical information about the origins of this pandemic exists in the People’s Republic of China, yet from the beginning, government officials in China have worked to prevent international investigators and members of the global public health community from accessing it.”
As debates about the origins of the pandemic and China’s role intensified, Mr. Biden ordered the nation’s intelligence agencies three months ago to draft a report on the source of the virus.
After the review, the National Intelligence Council and four other intelligence community elements reported that they believe the virus that causes Covid-19 was most likely created by “natural exposure to an infected animal through an animal infected with it, or close progenitor virus.”
Before the review was conducted only two agencies favored the natural exposure theory. But the new report said the intelligence council and other agencies favoring the natural theory only had only low confidence in their conclusions — a sign that the intelligence behind the assessment was not strong and that conclusions could change.
On the other side of the debate, one agency, with moderate confidence, said it had concluded that the pandemic was the result of “a laboratory-associated incident” in China. According to the declassified report, analysts at that agency gave weight to the risky nature of work on coronaviruses. The agency also said the accident likely involved “experimentation, animal handling, or sampling by the Wuhan Institute of Virology.”
There were two labs in Wuhan doing work on the coronavirus before the pandemic, but intelligence agencies have mostly focused on the work done at the Wuhan Institute of Virology.
The announcement from the director of national intelligence did not identify the agency that favored the laboratory-leak theory. But current and former officials said the F.B.I. believed that the virus was created within the lab. One former official said the bureau believed the virus likely escaped into the public from lab technicians.
The intelligence agencies all agree that the virus was unlikely to be created as any kind of biological weapon, the same stance the U.S. government has maintained for more than a year. The agencies also agree that the initial exposures that caused the outbreak occurred “no later than November 2019,” according to the declassified conclusions.
Critical to the debate over the virus origins, American intelligence officials do not believe the Chinese officials knew about it at the time of the outbreak, the report said.
“The IC assesses China’s officials did not have foreknowledge of the virus before the initial outbreak of Covid-19 emerged,” the declassified report said, using the initials for the intelligence community.
The three-month review ordered by Mr. Biden was done to bring more scientific expertise into the examination of the origins of the pandemic. Intelligence agencies used the three months to examine a trove of data that had not been fully combed through.
That data, taken from the Wuhan Institute of Virology, did not provide any additional information that persuaded any additional agencies that a lab leak was possible.
Mr. Biden said the United States would keep working with other nations and the World Health Organization to get access to more information from China.
“We must have a full and transparent accounting of this global tragedy,” he said. “Nothing less is acceptable.”