North Korea said Monday that leader Kim Jong Un observed test-flights of hypersonic missiles and underscored the need to bolster the country’s nuclear war deterrent, as the country dials up weapons displays ahead of its major political conference.

Axar.az informs, citing AP, North Korea reported on the drill a day after its neighbors said they detected multiple ballistic missile launches and accused the North of carrying out provocations. The tests came just hours before South Korean President Lee Jae Myung departed for China for a summit with President Xi Jinping.

The official Korean Central News Agency said Sunday’s drill involving a hypersonic weapon system was meant to examine its readiness, enhance missile troops’ firepower operational skills and evaluate operational capabilities of the country’s war deterrent.

“Through today’s launching drill, we can confirm that a very important technology task for national defense has been carried out,” Kim said, according to KCNA. “We must continuously upgrade the military means, especially offensive weapon systems.”