Sen. John Barrasso, R-Wyo., on Tuesday sent a letter to Energy Secretary Jennifer Granholm demanding answers and a classified briefing regarding the Energy Department's assessment that the COVID-19 pandemic likely originated from an accidental lab leak in China.

"I write to request that the Department of Energy provides expedited answers to questions regarding the department's release of an intelligence report concluding a lab leak was the most likely origin of the COVID-19 pandemic," Barrasso wrote in a letter obtained exclusively by Fox News Digital.

The Energy Department, which had been undecided on the origin of the pandemic, has now joined the FBI in concluding the coronavirus likely spread due to a mishap at a Chinese laboratory, according to the Wall Street Journal, which cited a classified intelligence report provided to the White House and "key members of Congress."

John Barrasso

Sen. John Barrasso talks to reporters at the U.S. Capitol Aug. 1, 2017. (Chip Somodevilla/Getty Images)

ANOTHER US AGENCY ASSESSES COVID-19 ORIGIN LIKELY A CHINESE 'LAB LEAK': REPORT

However, Barrasso didn't receive any news about the department's findings. 

"As ranking member of the Senate Committee on Energy and Natural Resources, a committee of jurisdiction on this sensitive matter, I was never provided this report nor informed of its conclusions. This is inexcusable," he wrote. "Accordingly, I am requesting the department immediately schedule a classified briefing to provide all members of Congress information pertaining to this report, as well as provide the 'new intelligence' that serves as the basis for the department's new lab leak determination."

The shift in the Energy Department's stance was reportedly noted in a classified 2021 document that was updated by Director of National Intelligence Avril Haines's office.

Barrasso requested the department provide a classified briefing to members of Congress no later than March 8 and answers to several questions no later than March 7. Those questions included the following:

china infectious disease researcher

A researcher works in a lab in Wuhan in central China, Hubei province, Oct. 12, 2021. (Feature China/Future Publishing via Getty Images)

GOP SENATORS PUSH BILL REQUIRING BIDEN DECLASSIFY ALL US INTELLIGENCE CONNECTED TO WUHAN LAB, COVID ORIGINS

  1. On what date did the department begin its efforts to determine the origins of the COVID-19 pandemic?
  2. On what date did the department reach the conclusion the COVID-19 pandemic originated from a lab leak?
  3. Please list the external government agencies the department partnered with that aided in the department's lab leak conclusion.
  4. Did the department work with any research institutions and/or universities in the course of its work to determine COVID-19's origins?If so, please list these entities.
  5. If so, please list these entities.
  6. Was the department at any point encouraged by any government employee or any private citizen to delay or withhold its findings surrounding its lab leak conclusion?
  7. Did the department work with the Chinese government or any Chinese government-sponsored individual or entity in ­any capacity during its COVID-19 origins research?If so, please describe these interactions in detail.
  8. If so, please describe these interactions in detail.
  9. Did the department work with the World Health Organization (WHO) in any capacity over the course of its COVID-19 origins research?If so, please describe these interactions in detail.
  10. If so, please describe these interactions in detail.
  11. Does the department plan to coordinate with the FBI and other members of the intelligence community to gather pertinent information in order to strengthen its determination stemming from its COVID-19 origins research?
BidenBiden and Xi stand in front of the Chinese and US flags

President Joe Biden meets with Chinese President Xi Jinping on the sidelines of the G-20 leaders' summit in Bali, Indonesia, Nov. 14, 2022. (Reuters/Kevin Lamarque)

CCP GOVERNMENT 'INTENTIONALLY RELEASED' COVID-19 'ALL OVER THE WORLD,' CHINESE VIROLOGIST SAYS

The so-called "lab leak theory," according to which COVID came from an accidental lab leak at the Wuhan Institute of Virology in Wuhan, China, was widely dismissed as a conspiracy theory and "misinformation" by Democrats, major news outlets, scientists, and social media companies in the early stages of the pandemic.

Following the Energy Department's assessment, Republican lawmakers demanded apologies from those who dismissed the lab leak theory and for China to be held accountable. They also called for answers and accountability from the Biden administration.

"China is responsible for COVID. The American people have a right to understand exactly how it was spread," Barrasso told Fox News Digital. "The Biden administration needs to come clean with what they know."

The Energy Department didn't immediately respond to a request for comment for this story.

Energy Secretary Jennifer Granholm speaks about rising gas prices

Energy Secretary Jennifer Granholm speaks during a press briefing at the White House, Nov. 23, 2021. (AP Photo/Evan Vucci, File)

REPUBLICANS ERUPT AFTER ENERGY DEPT REPORTEDLY SAYS COVID-19 LIKELY CAME FROM CHINESE LAB: 'WE NEED ANSWERS'

White House national security adviser Jake Sullivan was asked about the Wall Street Journal's report during a Sunday appearance on CNN.

"There is a variety of views in the intelligence community. Some elements in the intelligence community have reached conclusions on one side, some on the other. A number of them have said they just don’t have enough information to be sure," said Sullivan. "Here's what I can tell you: President Biden has directed repeatedly every element of our intelligence community to put effort and resources behind getting to the bottom of this question."

Beyond the FBI and Energy Department, the National Intelligence Council and four other agencies assess at "low confidence" that the COVID-19 pandemic originated due to natural transmission from an infected animal, while the CIA and another unnamed agency are undecided, according to the Journal.

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China, which has curtailed the WHO's investigations into the origins of COVID, has also rejected claims that the virus could have originated from one of its labs. The updated intelligence report showing the Energy Department's assessment maintains a consensus between all the intelligence agencies that the pandemic was not the result of a Chinese bioweapons program.