The International Atomic Energy Agency (IAEA) said on Friday that the containment structure at Ukraine’s Chernobyl nuclear plant, built to contain radioactive material from the 1986 disaster, can no longer perform its primary safety function after being damaged in a drone attack, which Ukraine has blamed on Russia.

The agency added that an inspection last week of the steel containment structure, completed in 2019, found that the drone strike in February had led to structural degradation, three years into the Russian war in Ukraine.