Ukraine’s state nuclear company, Enerhoatom, has rejected a plan by the UN’s nuclear watchdog to send a mission to the Russian-occupied Zaporizhzhya nuclear plant in southern Ukraine.

The nuclear plant — Europe’s largest — is under Russian control but still operated by Ukrainian staff amid heavy fighting between Russian and Ukrainian forces in the region.

The situation at the plant has been a source of concern for the International Atomic Energy Agency (IAEA) since Russia launched its invasion of Ukraine on February 24.

“We consider this message from the head of the IAEA as another attempt to get to the [power plant] by any means in order to legitimize the presence of [Russians] there and essentially condone all their actions,” Enerhoatom wrote in a post on Telegram.

On June 6, IAEA Director-General Raphael Grossi said the organization was working on sending an international mission of experts to the plant.

On June 5, Enerhoatom said a Russian cruise missile flew “critically low” over the nuclear power plant.