The United States accused Russia of deploying chemical weapons in Ukraine as a “instrument of war,” in violation of international law prohibiting the use of chemical weapons.
State Department officials said Russia used the choking agent chloropicrin to gain “battlefield gains” against Ukraine.
U.S. officials said the allegations were not an “isolated” incident and would violate the Chemical Weapons Convention (CWC), which Russia is a signatory to.
A Kremlin spokesman rejected the accusations as “baseless.”
Dmitry Peskov told reporters in Moscow that Russia complies with its obligations under the CWC, which prohibits states from developing or acquiring new weapons. Approximately 193 states have ratified the Convention.
The Organization for the Prohibition of Chemical Weapons (OPCW), the global watchdog that oversees the implementation of the CWC, states that chemical weapons are substances used to intentionally cause death or harm due to their toxic properties. .
Chloropicrin, which the United States claims was used by Russia to “dislodge Ukrainian troops from fortified positions,” is an oil-based substance widely used during World War I. According to the Centers for Disease Control and Prevention (CDC), it can irritate the lungs, eyes, and skin, and can cause vomiting, nausea, and diarrhea.
The use of this chemical in warfare is expressly prohibited by the CWC and is listed as a suffocating agent by the OPCW.
The State Department also said the Russian government regularly used “riot control agents,” or tear gas, during the war.
President Joe Biden previously warned Russia not to deploy chemical weapons in Ukraine. In March 2022, just weeks after Moscow launched its invasion, Biden vowed that President Vladimir Putin would pay a “severe price” if he authorized the use of chemical weapons.
“If he uses it, we will respond. The response will depend on the nature of the use,” Biden said.
However, there were consistent reports that Moscow ignored the warning. Mallory Stewart, the U.S. assistant secretary for arms control, has previously said Russia is using counterinsurgency personnel in the conflict.
And Ukraine said its military has been exposed to chemical attacks in recent months. Reuters reported earlier this year that the Russian military used grenades loaded with CS and CN tear gas.
The report added that at least 500 Ukrainian soldiers were being treated for exposure to toxic gas, and one died after suffocating from tear gas.
Three Russian entities linked to the country's biological and chemical weapons programs have been sanctioned by the State Department for their involvement in the production of chemical agents. Another company that donated to government agencies was also sanctioned.
In 2017, the OPCW announced that Russia had disposed of the last of its Cold War-era weapons stockpiles as required by the CWC.
However, Moscow has since been accused of making incomplete declarations about its stockpiles, according to the House of Commons Library.
Since 2017, Russia has been accused of at least two chemical attacks. One is the Salisbury attack on a former Soviet intelligence officer, and the other is the poisoning of late Russian opposition leader Alexei Navalny in 2020.
The allegations were made as part of broader U.S. sanctions targeting 30 people, including three who authorities say were involved in Navalny's death.
The men are all employees of a camp in Siberia where rebels were killed earlier this year. Russia denies involvement in the opposition leader's death.
Meanwhile, Russian forces in eastern Ukraine continue to advance steadily ahead of Victory Day on May 9, a holiday commemorating the Soviet Union's victory in World War II.
Much of the fighting has taken place around Chasiv Yar, a Kiev-controlled stronghold after Russia captured the city of Avdiivka. Moscow wants to seize the town ahead of next week's celebrations.
This follows President Volodymyr Zelenskiy's dismissal of Ilya Vityuk, the head of the cybersecurity department of the Security Service of Ukraine (SBU), who used his position to report corruption allegations against him. He is currently under suspicion that he was trying to punish a Ukrainian journalist who did so.
The reporter was then called to the military's recruitment center and was prompted by military commander Colonel Oleksandr Shirsky to launch an investigation.
The non-governmental organization Human Rights Watch is calling for a war crimes investigation after unearthing evidence that Russian forces executed more than a dozen surrendered Ukrainian troops. The incidents are said to have occurred between December 2023 and February 2024, authorities said in a statement.