Prominent social media users and conservative voices have amplified a baseless theory promoted by Russian state media accusing the United States of funding biological weapons laboratories in Ukraine.

There is no evidence to support the claims, which President Volodymyr Zelenskyy of Ukraine, the White House, the Pentagon and the State Department have all unequivocally denied. There are biological laboratories inside Ukraine, and since 2005, the United States has provided backing to a number of institutions to prevent the production of biological weapons.

But Fox News host Tucker Carlson and others have misleadingly cited remarks from American officials as proof that the labs are producing or conducting research on biological weapons.