Austrian Chancellor Sebastian Kurz blasted Turkish President Recep Tayyip Erdogan, saying that he is using migrants as a “weapon” against the European Union.

“This rush is not an accident, it’s organized,” Kurz told journalists in Vienna. “Those people are used by Erdogan as a playball, as a weapon, to apply pressure on the European Union.”

The European Union must stand united behind Greece, and protect the borders as well as provide humanitarian help, Kurz said.

Kurz said Erdogan “consciously organized” the action, that “buses are provided, migrants are informed, there’s a deliberate attempt to organize this rush on Greece.” The refugees at the border aren’t from Idlib or from other regions in Syria, but have been in Turkey for many years, he said.

The Austrian Chancellor also called the actions by Turkey an “attack” in numerous Tweets.