The North Korean delegation, led by Kim Yong-jae, minister of external economic relations, left for Vladivostok for the Third Oriental Economic Forum, the North's Korean Central News Agency reported.
Moon is scheduled to head there Wednesday for a two-day visit that will include a bilateral summit with Russian President Vladimir Putin.
The South Korean president earlier noted he expected to see North Korean officials at the forum. He did not say whether he planned to hold talks with any of them.
Moon's trip to Russia is partly aimed at winning Moscow's support for new and stronger sanctions against the communist North for its latest nuclear test staged Sunday.
The nuclear test, the sixth of its kind, has prompted strong condemnation from nearly all regional powers, including China, the North's only communist ally. (Yonhap)