The Russian nuclear exercises are "definitely sabre-rattling" and a "continuation of Russia's irresponsible behaviour," a European Commission spokesman said on Monday.
At a press conference in Brussels, Peter Stano - a spokesman for European Union foreign affairs chief Josep Borrell - said the move is "yet another proof that the Kremlin is only interested in further escalating the situation which was caused by its illegal aggression against Ukraine."
"We call on Russia to stop the escalation, to stop the irresponsible rhetoric," Stano said.
He added that Russia should cease its aggression against Ukraine and "the related violations of international laws and of international obligations which Russia took on itself."