U.S. intelligence agencies delivered a report to Biden on the virus’s origins.

The director of national intelligence on Tuesday delivered a report to President Biden on the origins of the coronavirus epidemic, according to U.S. officials, but the nation’s spy agencies have not yet concluded whether the disease was the result of an accidental leak from a lab or if it emerged naturally in a spillover from animals to humans.

Mr. Biden had ordered the nation’s intelligence agencies three months ago to draft a report on the origins of the virus amid an intensifying debate over questions about its provenance, and in part to give the agencies a chance to examine a trove of data that had not been fully exploited.

But the inquiry, which examined data collected from a virology research institute in Wuhan, China, the city where the virus first spread, has yet to answer the biggest outstanding question about where it came from. Its absence of conclusions underscores the difficulty of pinpointing the source of the virus, particularly given China’s refusal to continue to cooperate with international investigations into the origin of Covid-19.

In the months after the coronavirus pandemic broke out globally, intelligence agencies began looking into how it started. Former Secretary of State Mike Pompeo pushed the agencies to look into the theory that the virus was created inside a Chinese lab and accidentally leaked. Mr. Pompeo formed his own research group to study the question.

During the Trump administration, intelligence agencies ruled out theories that the virus was deliberately leaked. But they said they could not make a conclusion about what was more likely: an accidental leak from a lab researching coronaviruses or a natural development of the virus.

While many scientists were initially skeptical of the lab leak theory, at least some became more open to examining it this year. And some criticized a World Health Organization report in March that found the lab leak theory unlikely.

After that report, Biden administration officials became frustrated with a decision by the Chinese government to stop cooperating with further investigations by the World Health Organization into the origins of the pandemic. In the face of what they called Chinese intransigence and a divided American intelligence community, Biden administration officials then ordered a 90-day review of the intelligence, resulting in the report delivered to the president on Tuesday.

Current and former officials have repeatedly warned that finding the precise origins of the pandemic may be more of a job for scientists than spies. Under Avril D. Haines, the director of national intelligence, the agencies have stepped up cooperation with scientists, hoping to better understand the current pandemic and possible future ones.

Officials also warned that the 90-day review was probably too short a time to draw any definitive conclusions.

The report remains classified for now, and officials would not discuss its findings. But officials said that Ms. Haines’s office would most likely declassify some information later this week.

“It typically takes a couple of days, if not longer, to put together an unclassified version,” Jen Psaki, the White House press secretary, said Monday.