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The White House on Wednesday warned that Russia could use "chemical or biological weapons in Ukraine" or could create a "false flag operation" using them, after the Kremlin accused the U.S. of being involved in biological weapons research at Ukrainian labs.

The director of the Russian Ministry of Foreign Affairs’ information and press department, Maria Vladimirovna Zakharova, said that in the course of Russia’s invasion of Ukraine, Russia confirmed that Ukrainian leadership was quickly trying to clean up any trace of "military and biological programs" that Ukraine was conducting with financial backing from the United States.

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This echoed previous accusations that the Kremlin has made about Ukraine allegedly destroying samples of various pathogens. A spokesperson for Ukrainian President Volodymyr Zelenskyy denied the allegations, according to Reuters, and a senior U.S. defense official called the claims "laughable" and said they are part of a Russian disinformation campaign.

On Wednesday, White House press secretary Jen Psaki said the administration "took note of Russia’s false claims about alleged U.S. biological weapons labs and chemical weapons development in Ukraine," and added that officials have also seen "Chinese officials echo these conspiracy theories."

White House press secretary Jen Psaki

White House press secretary Jen Psaki speaks during a press briefing at the White House, Friday, March 4, 2022. (AP Photo/Carolyn Kaster) (AP Newsroom)

"To be clear: this is preposterous," Psaki said, adding that it is "exactly the kind of disinformation operation we’ve seen repeatedly from the Russians over the years in Ukraine and in other countries around the world, which have been debunked conclusively, and an example of the types of false pretexts we have been warning the Russians would invent."

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Psaki said the U.S. is "in full compliance with its obligations under the Chemical Weapons Convention and the Biological Weapons Convention and does not develop or possess such weapons anywhere."

"It’s Russia that has a long and well-documented track record of using chemical weapons, including in attempted assassinations and poisoning of Putin’s political enemies like Alexey Navalny," Psaki said. "It’s Russia that continues to support the Assad regime in Syria, which has repeatedly used chemical weapons. It’s Russia that has long maintained a biological weapons program in violation of international law."

Psaki also pointed to Russia’s "track record of accusing the West of the very violations that Russia itself is perpetrating."

In December, Psaki reminded that Russia "falsely accused the U.S. of deploying contractors with chemical weapons in Ukraine."

"This is all an obvious ploy by Russia to try to justify its further premeditated, unprovoked, and unjustified attack on Ukraine," she said.

"Now that Russia has made these false claims, and China has seemingly endorsed this propaganda, we should all be on the lookout for Russia to possibly use chemical or biological weapons in Ukraine, or to create a false flag operation using them," Psaki warned.

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She added: "It’s a clear pattern, and no one should fall for it."

And a senior defense official also said Russia's allegations against the U.S. are "a piece of the Russian playbook here: claim they're the victims, create a false narrative to try to justify their own aggressive actions." 

"It is absurd. It is laughable. It is untrue," the official said. 

The defense official’s rejection of the Russian narrative came after Undersecretary of State for Political Affairs Victoria Nuland told the Senate Foreign Relations Committee on Tuesday that Ukraine does have labs, and that the U.S. was helping them keep Russia from taking them over.

Ukrainian emergency employees and volunteers carry an injured pregnant woman from the damaged by shelling maternity hospital in Mariupol, Ukraine, Wednesday, March 9, 2022. A Russian attack has severely damaged a maternity hospital in the besieged port city of Mariupol, Ukrainian officials say.

Ukrainian emergency employees and volunteers carry an injured pregnant woman from the damaged by shelling maternity hospital in Mariupol, Ukraine, Wednesday, March 9, 2022. A Russian attack has severely damaged a maternity hospital in the besieged port city of Mariupol, Ukrainian officials say. (AP Photo/Evgeniy Maloletka)

"Ukraine has biological research facilities which in fact we are quite concerned Russian troops, Russian forces, may be seeking to gain control of, so we are working with the Ukrainians on how they can prevent any of those research materials from falling into the hands of Russian forces should they approach," Nuland said.

Nuland said this in response to a question from Sen. Marco Rubio, R-Fla., about whether Ukraine had chemical or biological weapons. 

damaged logistic center after shelling in Kyiv

Firefighters work to extinguish a fire at a damaged logistic center after shelling in Kyiv, Ukraine, Thursday, March 3, 2022. Russian forces have escalated their attacks on crowded cities in what Ukraine's leader called a blatant campaign of terror. (AP Photo/Efrem Lukatsky) (AP Photo/Efrem Lukatsky)

Nuland said that if there is any biological or chemical attack in Ukraine, "there is no doubt in my mind" that it would be carried out by Russia, and that it is "classic Russian technique to blame on the other guy what they’re planning to do themselves."

This is not the first time that Russia has accused the U.S. of backing biological weapons labs near its borders. In 2018, the Kremlin alleged that the U.S. was funding a secret biological weapons lab in the country of Georgia, which they claimed was one of several labs the U.S. had near the borders of Russia and China.

A Pentagon spokesperson denied this at the time.

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Meanwhile, the Office of the Director of National Intelligence on Tuesday released its 2022 annual threat assessment, which was submitted in early February. The assessment only includes intelligence through the end of January—weeks before Russia launched its multi-front war against Ukraine.

In its assessment, though, the intelligence community said that Russia will remain "the largest and most capable" rival in weapons of mass destruction to the United States "for the foreseeable future," as it "expands and modernizes its nuclear weapons capabilities and increases the capabilities of its strategic and nonstrategic weapons."

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"Russia is expanding and modernizing its large, diverse, and modern set of nonstrategic systems, which are capable of delivering nuclear or conventional warheads," the report states, adding that Moscow believes such systems "offer options to deter adversaries" and "control the escalation of potential hostilities."

Fox News' Pat Ward, Ronn Blitzer, Jennifer Griffin and The Associated Press contributed to this report.