United Nations nuclear inspectors have found no evidence to back Russia’s claims that Ukraine is building a radiological weapon known as a “dirty bomb.” Ukraine’s president Volodymyr Zelensky spoke Thursday.

President Volodymyr Zelensky: “We have invited the IAEA to check. We have given them complete freedom of action at the relevant facilities. And we have clear and irrefutable evidence that no one in Ukraine has created or is creating any dirty bomb.”

In Zaporizhzhia, the operator of Europe’s largest nuclear power plant says the facility has two weeks of diesel fuel for its backup generators. IAEA Director General Rafael Grossi has reiterated calls for a security protection zone around the Zaporizhzhia plant after fighting once again severed outside power to the plant’s cooling systems, which are critical to preventing a radiation disaster. Grossi said Thursday that reliance on diesel generators is “clearly not a sustainable way to operate a major nuclear facility.”