The Kremlin is accusing the U.S. of being involved in biological weapons research at Ukrainian labs, but such claims are "laughable" and part of a Russian disinformation campaign, according to a senior U.S. defense official.

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

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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.

"The Russian narrative that they've put out there that the United States is somehow running or facilitating, you know, biological weapons labs in Ukraine and that these labs are going to pose a threat to the – this is of a piece of the Russian playbook here: claim they're the victims, create a false narrative to try to justify their own aggressive actions," the U.S. defense official said Wednesday. "It is absurd. It is laughable. It is untrue."

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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.

"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.

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

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."

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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, calling the claims "an invention of the imaginative and false Russian disinformation campaign against the West" and "obvious attempts to divert attention from Russia’s bad behavior on many fronts."

Fox News’ Jennifer Griffin and The Associated Press contributed to this report.