United States President Joe Biden tasked the US intelligence community on Wednesday to escalate its investigation into the origins of the coronavirus pandemic.

The president gave intelligence agencies 90 days to report back to him on their findings, saying he asked “for areas of further inquiry that may be required, including specific questions for China.”

“I have also asked that this effort include work by our National Labs and other agencies of our government to augment the Intelligence Community’s efforts. And I have asked the Intelligence Community to keep Congress fully apprised of its work,” Biden said in a statement.

Biden said that so far the intelligence community has “coalesced around two likely scenarios” regarding the origins of Covid-19 (coronavirus disease 2019), but noted they have not “reached a definitive conclusion on this question.”

Both scenarios have been assessed with low or moderate confidence, with two agencies leaning toward one scenario, and a third leaning toward the other, Biden said. But he noted, “the majority of elements do not believe there is sufficient information to assess one to be more likely than the other.”

Biden did not specify which scenarios are being considered but there has been growing debate about whether the virus emerged from a laboratory or was a natural development.

The Wall Street Journal reported on Sunday that three researchers at China’s Wuhan Institute of Virology became seriously ill in November 2019 and required hospital care to treat symptoms consistent with a Covid-19 infection and other seasonal illnesses.

The report was based on US intelligence.

The pandemic is widely regarded as beginning in December 2019 in the Chinese city of Wuhan. It has claimed more than 3 million lives and infected 167 million people since it was first detected, according to data collected by Johns Hopkins University.