"The scale of deployed North Korean troops is being closely watched," Yoon Yeocheol, South Korea's ambassador to the U.K., told Newsweek.

On the one hand, the deployment of the North Korean troops seems a logical follow-up to the mutual defense treaty signed by Kim Jong-un and Vladimir Putin in Pyongyang in June. On the other hand, it raises a series of important questions.

In a joint press conference on Friday at the APEC summit in Lima, Peru, US President Joe Biden, South Korean President Yoon Suk-yeol, and Japan’s Prime Minister Shigeru Ishiba warned of the latest “dangerous and destabilizing” cooperation between Russia and North Korea.