Britain and the US fear Russia could be setting the stage to use a chemical weapon in Ukraine after Kremlin officials alleged without firm evidence that the US had been supporting a bioweapons programme in the country.
White House press secretary Jen Psaki said on Wednesday that Russia had been making “false claims about alleged US biological weapons labs and chemical weapons development in Ukraine”, and added that the allegations had been echoed in Beijing.
“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,” she tweeted.
Her comments came after western officials said at a briefing “we’ve got good reason to be concerned about possible use of non-conventional weapons” by Russia, reflecting the experience of chemical weapon use during the Syrian civil war.
The concern arose partly because Russia’s foreign ministry had been engaged in “setting the scene” by making “false flag claims” about a biological weapons programme operating inside Ukraine.
Earlier on Wednesday, Russian foreign ministry spokesperson Maria Zakharova said Russia had documents showing evidence that the US had supported a bioweapons programme in Ukraine, involving plague, cholera and anthrax. Washington and Kyiv both denied the claims, which Psaki described as “preposterous”.
Separately, Russia’s defence ministry accused “Ukrainian nationalists” of preparing a chemical weapons “provocation” in a village north-west of Kharkiv. The plan was to falsely accuse Russian forces of using chemical weapons, the ministry added.
“Russia has a track record of accusing the west of the very violations that Russia itself is perpetrating,” Psaki tweeted. “This is all an obvious ploy by Russia to try to justify its further premeditated, unprovoked and unjustified attack on Ukraine.”
Western officials have repeatedly made warnings about Russia’s possible use of particularly lethal weapons over the past two weeks, such as thermobaric vacuum bombs which cause severe damage to human bodies because of the intensity of their explosive blasts.
Such high-profile warnings from the west are as much designed to have a deterrent effect as they are based on any assessment that such weapons will actually be used.
But Russia has shown an apparent willingness to target civilians in Ukrainian cities such as Kharkiv and Mariupol, as its initial invasion was slow in making progress.
Direct attacks on civilians or civilian infrastructure are considered war crimes. The development, production and stockpiling and use of chemical weapons is banned by an international treaty signed by 193 countries.
Chemical weapons have nevertheless been used on at least 17 occasions during Syria’s civil war, according to the Organisation for the Prohibition of Chemical Weapons (OPCW), which has accused the Russian-backed regime of Bashar al-Assad of being behind several high-profile attacks.
In recent years, however, Russia, has sought to deny that the Syrian regime has used chemical weapons – and in April 2018, without supporting evidence, accused Britain of being behind a chlorine attack in Douma that killed 40.
But the fact that the chemical weapons involved were delivered through airstrikes led the OPCW to conclude the Syrian air force was responsible.
Western officials believe that Russia’s military advance has been “very slow” in recent days, because of greater than expected Ukrainian resistance and poor planning and logistics on the part of Moscow. But they accept Russian forces are making gradual progress, and are trying to “tighten the noose” around Kyiv, the capital.
One official said they believe the Russian army was “re-posturing and trying to learn lessons” as its forces advanced toward Kyiv from the east while also remaining in position to the north-west of the city.
An attack on Kyiv would be “absolutely horrific” but no timeframe was put on whether it would be possible.
Earlier this week, the Institute for the Study of War, a US thinktank, said it believed Russian forces were gradually building up for an attack on Kyiv “in the coming 24-96 hours”.
But it remains unclear if Moscow can concentrate enough force to begin an attack on the capital, which before the war had a population of 3 million.