The European Union led a walkout of delegates from a meeting of the U.N. nuclear watchdog’s Board of Governors on Wednesday in protest at “unacceptable” remarks by Russia, the EU ambassador to the International Atomic Energy Agency said.

“EU initiates a broad walk-out … in response to unacceptable remarks by #Russia. We strongly condemn Russian military aggression against #Ukraine & resulting nuclear threats to safety of Ukrainian facilities,” Stephan Klement said on Twitter. The EU also chairs the separate Iran nuclear talks.