MUKACHEVO, Ukraine — The United States and its allies have intelligence that Russia may be preparing to use chemical weapons against Ukraine, U.S. and European officials said Friday, as Moscow sought to invigorate its faltering military offensive through increasingly brutal assaults across multiple Ukrainian cities.
The accusations surfaced as Russia repeated claims that the United States and Ukraine were operating secret biological weapons labs in Eastern Europe — an allegation that the Biden administration dismissed as “total nonsense” and “outright lies.”
Any use of poison gases in Ukraine would violate a decades-old international treaty banning such weapons, and represent a dangerous turn in Russia’s two-week-old military offensive against its neighbor. Russia, which possessed vast stocks of chemical and biological weapons during the Cold War, has used outlawed nerve agents in at least two assassination attempts against political foes of President Vladimir Putin in the past three years, including at least once outside its borders, Western intelligence agencies concluded.
Because the U.S. and European officials declined to describe the nature of the intelligence pointing to a possible Russian chemical attack in Ukraine, it was impossible to determine how significant it might be. U.S. officials have been warning publicly for days that Russia might carry out a false flag operation, after the Kremlin alleged the United States had supported a bioweapons program in Ukraine.
“It’s more than an urgent concern,” one European official said of the prospects for a Russian chemical attack. “Clearly there’s been an increase in the threat.”
A senior NATO official added that Russia “is preparing the ground for a chemical or bioweapons attack.”
Elsewhere on Friday, Russian forces intensified a relentless bombing and artillery campaign against cities and towns across a widening swath of southern and central Ukraine. Four Ukrainians were killed and six others were wounded Friday in missile attacks by Russian forces on a military airfield in Lutsk, said Yuriy Pohulyayko, governor of the surrounding Volyn region. Another military airfield in Ivano-Frankivsk, in western Ukraine, was also struck by missiles. New satellite imagery, meanwhile, showed a massive Russian convoy outside Kyiv maneuvering in possible preparation for an assault against the capital.
According to the latest figures from the United Nations, 564 civilians have been confirmed killed and 982 injured, though the true toll is probably far higher.
Russian forces continued to suffer substantial losses, as Ukrainian troops armed with antitank weapons and armed drones beat back invading forces along several fronts. But the methodical demolishing of Ukrainian urban centers by Russian missiles and artillery has contributed to a mounting humanitarian catastrophe, according to Ukrainian officials and international relief agencies. The mayor of Mariupol described his besieged southern port city as going through “Armageddon.”
The United Nations’ human rights office said it has received “credible reports” of Russia using cluster bombs, including in the key eastern city Kharkiv, which could constitute war crimes. Almost 2.5 million refugees have fled Ukraine during Moscow’s attack, according to the U.N.
In the latest economic salvo against Russia, President Biden called on Congress Friday to end normal trade relations with Russia and announced a new slate of bans on Russian imports and exports. Meanwhile, YouTube joined a growing number of Western companies to restrict business in Russia, announcing that it was blocking Russian state media channels worldwide. The move followed an announcement by Russia that it intended to block the social media platform Instagram and to declare Facebook an extremist organization — actions that show how the Kremlin is increasingly willing to censor free expression and retaliate against tech companies.
Fears that Moscow might introduce nonconventional weapons into the Ukrainian conflict have intensified in the wake of Russian failures to quickly to capture major Ukrainian cities. As the war’s momentum has slowed, Russian diplomatic and military officials have stepped up accusations about supposed secret biological weapons laboratories in Ukraine.
On Friday, Russian representative to the U.N., Vasily Nebenzya, told the body’s Security Council that Russia had discovered “truly shocking facts” related to what he said were at least 30 Ukrainian laboratories working on diseases including anthrax, cholera, and “the plague” with funding and oversight by the U.S. military. He said the “reckless” activity included research related to diseases born by birds, lice and fleas.
The claim recycled unproven accusations voiced by Russian officials since the start of the Putin era, and amplified by state-run Russian news media. No verifiable evidence has ever been put forward to substantiate the allegations, which a Pentagon official dismissed on Friday as “absurd and laughable.”
The United States helped Ukraine improve security at several Soviet-era biological research facilities at the end of the Cold War under the Pentagon’s Cooperative Threat Reduction Program. Ukraine has five biological research centers that are focused on disease prevention and treatment, under guidelines set by the Biological Weapons Convention and approved by countries around the world, including Russia, current and former Pentagon officials said. On Friday, the U.N.'s high representative for disarmament affairs, Izumi Nakamitsu, said the world body was unaware of any biological weapons program in Ukraine.
Still, Russia’s sudden vehemence in repeating the accusations has stoked fears that Moscow may be creating a pretext for its own use of chemical or biological agents in Ukraine.
“Russia is attempting to use the Security Council to legitimize disinformation and deceive people to justify President Putin’s war of choice against the Ukrainian people,” Linda Thomas-Greenfield, the U.S. ambassador to the U.N., said at Friday’s Security Council meeting. She also accused China of echoing the false allegations, effectively “spreading disinformation in support of Russia’s outrageous claims.”
Britain’s representative to the United Nations, Lady Barbara Woodward, called the bioweapons claim “utter nonsense.”
“Russia is sinking to new depths today, but this council must not get dragged down with it,” she said.
During Syria’s civil war, Russia repeatedly provided diplomatic cover and logistical aid to President Bashar al-Assad when Syrian forces used chemical weapons against opposition-held neighborhoods. The Syrian chemical attacks, intended to undermine rebel morale and drive insurgents out of urban barricades, included sophisticated and highly lethal nerve agents, as well ordinary industrial compounds such as chlorine. In the worst attack, in August 2013, deadly sarin gas seeped into basements used by Syrian families as bomb shelters, killing an estimated 1,400 people.
The Syrian attacks often were accompanied by false-flag claims — repeated frequently by Russian officials — suggesting that rebels themselves were behind the attacks.
According to the NATO official who described the growing angst about potential chemical attacks in Ukraine, the concern is being driven by new “intel, and also Russia’s previous record of the tactics.”
The official described the tactics as consisting of “heavy bombardment, flattening of cities, then chemical weapons use to clean basements of fighters, then denying and planting false flags.”
A second European official also cited new intelligence suggesting possible preparations for a chemical attack, but decline to elaborate. U.S. officials declined to comment on intelligence assessments. A senior Defense official said that Ukraine’s government has not requested protective equipment for defending against a chemical attack.
Ukrainian forces, facing slow but steady advances from Russian troops, have urgently appealed for other assistance, including advanced weaponry. NATO countries want to help, officials say, but can only provide what Ukraine’s troops can actually use based on their existing training.
The most useful weapons systems are Soviet- and Russian-made ones that are in the arsenals of former communist countries in Eastern Europe. Among other things, Ukrainian officials are seeking stepped-up deliveries of antitank weapons because they see it as the only way to break the progressive encirclement of their cities, according to a senior European diplomat. The weaponry would be used to create humanitarian corridors in and out of the cities, the diplomat said.
Putin, meanwhile, on Friday approved recruiting foreign “volunteers” to reinforce the Russian military’s invasion of neighboring Ukraine.
“If you see that there are people who want to come voluntarily, especially free of charge, and help people living in the Donbas, you need to meet them halfway and help them move to the war zone,” Putin told his defense minister, Sergei Shoigu, during a televised Russian Security Council meeting Friday.
Donbas is a region of eastern Ukraine where Moscow-backed separatists have declared independent “republics” and where Putin has baselessly accused Ukraine of committing a genocide against Russian speakers.
Shoigu said that Moscow has received “a colossal number of applications” from across the world to join what it is calling a “Ukrainian liberation movement.” The defense minister said the Kremlin got more than 16,000 applications, of which most came from the Middle East.
Adela Suliman in London, and Timothy Bella, Maite Fernández Simon and Dan Lamothe in Washington contributed to this report.