On September 4, members of the NATO defense alliance will hold a special session to discuss the poisoning of Russian opposition leader Aleksei Navalny with a military-grade nerve agent Novichok.

The 30-member Western military alliance is expected to formally call on Russia to conduct a full and transparent investigation, but more concrete measures are unlikely to be immediately announced.

NATO chief Jens Stoltenberg is scheduled to speak at a press conference after the meeting. “We’ll consult with Germany and all NATO Allies on the implications,” Stolenberg said.

Earlier this week, on September 2, the German government announced that Navalny had been poisoned with the military-grade nerve agent Novichok, the same chemical weapon British authorities say was used against Russian double agent Sergei Skripal in 2018.