International Atomic Energy Agency(IAEA) Director General Rafael Grossi said North Korea is constructing a new building at Yongbyon, with dimensions and features similar to the regime's Kangson enrichment plant near Pyongyang.

Reporting to the IAEA Board of Governors on Monday, Grossi shared such information, before expressing deep regret over the North's continuation and further development of its nuclear program in violation of UN Security Council resolutions.

The North is suspected of having undeclared enrichment facilities at both Yongbyon and Kangson, with possibility for construction of additional facilities.

Japan and some other countries are expected to release a joint statement at the board meeting to express concern over the North's nuclear activities.

Seoul's foreign ministry said it is monitoring related trends in close coordination with allies and friendly nations, including the U.S., urging the regime to immediately halt its nuclear activities and return to the path of denuclearization and dialogue.