Ukrainian Defense Minister Oleksii Reznikov said Russia's accusation that Ukraine is planning to use a radioactive device is "all fake" and "an act of Russian nuclear blackmail."
He made the remarks during phone talks with his French, British and Turkish counterparts on Monday.
Russian Defense Minister Sergei Shoigu voiced concern Sunday to his counterparts from the United States, Britain, France and Türkiye about "possible Ukrainian provocations involving a 'dirty bomb.'"
The foreign ministers of the United States, Britain and France reiterated their support for Ukraine in a statement late Sunday, and said their defense ministers made clear to Shoigu their rejection of "Russia's transparently false allegations."