If Putin wins, it would show countries like China that "brute force" works, he said.
"Beijing is watching closely. And learning lessons that may influence its future decisions," he warned.
NATO Secretary General Jens Stoltenberg on Tuesday warned that a Russian victory in the war it launched against Ukraine would send a "dangerous" message to authoritarian regimes around the world.
"Beijing and Moscow are leading an authoritarian pushback against the international rules-based order. The Indo-Pacific faces growing challenges, from China's coercive behaviour to provocations by North Korea," Stoltenberg said at a joint press conference with Japanese Prime Minister Fumio Kishida in Tokyo, going on to characterize Russia's "brutal war of aggression against Ukraine" as not only a crisis for Europe but a "challenge to the world order."
"If President Putin wins in Ukraine, this would send a message that authoritarian regimes can achieve their goals through brute force. This is dangerous. Beijing is watching closely. And learning lessons that may influence its future decisions," the NATO chief said. "What is happening in Europe today could happen in East Asia tomorrow. So we must remain united and firm. Standing together for freedom and democracy."