Russia has announced that it will not ask the UN Security Council to vote on Friday over its draft resolution on humanitarian relief for Ukraine, which has been criticised for making no mention of Moscow’s invasion of its neighbour.

It will instead use the scheduled council session to again raise allegations that the United States has biological warfare laboratories in Ukraine, claims that Washington says are disinformation and part of a potential “false-flag operation” by Moscow.

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Russia’s UN ambassador, Vassily Nebenzia, made the announcement at a Security Council meeting Thursday afternoon that was called by six Western countries, including the United States, to get an update on the three-week-old war.

He said Russia is not withdrawing the resolution but decided not to seek a vote at this time because of what he called “unprecedented pressure” from Western nations, especially the United States and Albania, on UN member states to oppose the measure.

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Nebenzia said Russia plans to go ahead with the council meeting Friday to discuss again its allegations that there are US military biological laboratories in Ukraine. Russian diplomats have presented no evidence to support its claim, which has been repeatedly denied by both the US and Ukraine.

US Ambassador Linda Thomas-Greenfield responded to Nebenzia’s announcement by saying that “their farcical humanitarian resolution … was doomed to fail.”

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“We know if Russia really cared about humanitarian crises — the one that it created — it could simply stop its attacks on the people of Ukraine,” she said. “But instead, they want to call for another Security Council meeting to use this council as a venue for its disinformation and for promoting its propaganda.”

At last Friday’s council meeting on Russia’s initial allegations of US “biological activities,” Thomas-Greenfield accused Russia of using the council for “lying and spreading disinformation” as part of a potential false-flag operation by Moscow for the use of chemical or biological agents in Ukraine.

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She said Russia was playing out a scenario put forth in the council last month by US Secretary of State Antony Blinken — that Russian President Vladimir Putin would “fabricate allegations about chemical or biological weapons to justify its own violent attacks against the Ukrainian people.”

Nebenzia said last week Russia’s Defence Ministry holds documents charging that Ukraine has at least 30 biological laboratories carrying out “very dangerous biological experiments” involving pathogens, and the work “is being done and funded and supervised by the Defence Threat Reduction Agency of the United States.”

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He said Thursday that he will present documents at the council meeting Friday.

Ukraine does have a network of biological labs that have gotten funding and research support from the US. But they are owned and operated by Ukraine and are part of an initiative called the Biological Threat Reduction Program that aims to reduce the likelihood of deadly outbreaks, whether natural or manmade. The US efforts date back to work in the 1990s to dismantle the former Soviet Union’s program for weapons of mass destruction.