The United States and Western allies slammed Russia on Friday for spreading propaganda, disinformation and "nonsense" at the United Nations Security Council by alleging that parts of biological weapons were being made in Ukraine.

Russia's U.N. Ambassador Vassily Nebenzia sent a lengthy document, seen by Reuters, to the council and U.N. Secretary-General Antonio Guterres on Friday on Moscow's accusation that there are "military biological programs" in Ukraine.

"The Ministry of Defense is receiving more and more material and analyzing that. We will continue to keep the international community informed about the unlawful activity carried out by the Pentagon on Ukrainian territory," Nebenzia told the council.

It was the second time in two weeks that the 15-member council met on the topic at Russia's request. Britain's U.N. Ambassador Barbara Woodward described Russia's move as "disinformation of the desperate."

"We've had a rehash of amateurish disinformation, which we discussed and debunked last Friday. It was nonsense then, and it is nonsense now," she told the council on Friday.

The United Nations has said it was not aware of any biological weapons programs in Ukraine, and U.N. disarmament affairs chief Izumi Nakamitsu told the council on Friday that the world body does not have "the mandate nor the technical or operational capacity" to investigate Russia's information.

The U.S. ambassador to the United Nations, Linda Thomas-Greenfield, on Friday accused her Russian counterpart of "a tirade of bizarre conspiracy theories" last week.

"This week we're hearing a whole lot more where that came from, things that sound like they were forwarded to him on a chain email from some dark corner of the internet. President Biden has a word for this kind of talk: 'Malarkey,'" she said.

Thomas-Greenfield also said "it is possible that Russia may be planning to use chemical or biological agents against the Ukrainian people," but did not cite any evidence for Washington's concerns.

Russia called the meeting on Friday to replace a planned vote on a Russian-drafted call for aid access and protection of civilians in Ukraine. Diplomats said the measure would have failed, while Nebenzia accused Western countries of a campaign of "unprecedented pressure" against it.