The World Health Organization told Reuters on Thursday that it advised the Ukrainian Health Ministry to destroy "high-threat pathogens" held in labs around the time Russia invaded Ukraine.

"As part of this work, WHO has strongly recommended to the Ministry of Health in Ukraine and other responsible bodies to destroy high-threat pathogens to prevent any potential spills," the WHO said in response to questions about its work with Ukraine before and during Russia's invasion.

The WHO would not specify what kinds of pathogens were housed in the Ukrainian labs, nor would it say when it advised Ukraine to destroy them. Russia claims to have documents that show the Ukrainian Health Ministry ordered the destruction of samples of plague, cholera, anthrax, and other pathogens kept at US-linked labs around the time Russia launched its attack on February 24.