"China, Iran, and North Korea pose challenges individually and through their cooperation. Just look at the images from Beijing over the past few days and the hand-holding," Rutte said at the International Institute for Strategic Studies (IISS) Prague Defense Summit.
"They are preparing for long-term confrontation. As I said earlier, these challenges are enduring, so we must be prepared," Rutte was quoted as saying by The Guardian.
China held a major military parade in Beijing on Wednesday, marking the 80th anniversary of Japan's surrender in World War II.
President Xi Jinping, flanked by Russian President Vladimir Putin and North Korean leader Kim Jong Un, used the parade to project China's military strength.
Iranian President Masoud Pezeshkian appeared to be nearer the back of assembled heads of state and was not pictured greeting Xi.
"Russia’s unprovoked war against Ukraine is the most obvious example of this threat. But the threat will not end when this war does, nor is it limited to Russia," Rutte said.