German Chancellor Olaf Scholz called on Thursday for an extraordinary NATO summit to discuss a response to Russia’s military intervention in Ukraine.

He told a news conference in Berlin that Russia’s attack is a clear violation of international law, and Germany will coordinate its response with European partners and NATO allies.

“Together with the French president, I would like to call for an in-person meeting of NATO heads of state and government in order to discuss the situation,” he said, adding that Russia’s aggression was also an attack on the European security order.

Scholz told reporters that he will be traveling to Brussels later in the day to join leaders of EU member states to discuss latest developments and approve additional sanctions.

“The aim of our sanctions is to make it clear to the Russian leadership that they will pay a high price for this aggression,” he said.

Sharply criticizing Russian President Vladimir Putin, Olaf said nothing could ever justify the bombardment of Ukrainian citizens that puts countless innocent lives at risk.

“Putin has made a terrible mistake by unleashing this war,” he said.

Putin announced a military intervention in Ukraine early Thursday, just days after recognizing two separatist-held enclaves in eastern Ukraine.

He said the action followed a request for help from authorities of Donetsk and Luhansk, claiming that Moscow had no plan to occupy the neighboring territory, but wanted to “demilitarize” and “denazify” Ukraine.