SEOUL, South Korea (AP) — North Korean leader Kim Jong Un observed sea trials of a new warship repaired after a failed launch last year and vowed to accelerate efforts to build a nuclear-armed navy, state media said Saturday, showcasing his expanding military capabilities ahead of a visit by Chinese leader Xi Jinping.

North Korea’s official Korean Central News Agency said Kim visited the 5,000-ton destroyer Kang Kon on Thursday as it underwent capability tests. Photos released by the agency showed him accompanied by his increasingly prominent teenage daughter, believed to be named Kim Ju Ae, whom South Korean officials say may be being groomed as his successor.

Kim Jong Un called for “rapidly developing” naval forces capable of playing a larger role in the country’s nuclear deterrent and dealing a “deadly blow at the enemy any moment under the water or on the water,” KCNA said. He said the navy was a key focus of a new five-year defense plan approved at a ruling party congress earlier this year, which he said includes building larger 10,000-ton-class destroyers and developing unspecified “underwater secret weapons.”

The agency did not report any direct remarks by Kim about Washington or Seoul amid persistent tensions over his nuclear ambitions and a prolonged freeze in diplomacy. The report came a day after North Korean and Chinese state media confirmed that Xi would visit North Korea on Monday, the latest sign of Beijing’s efforts to reinforce ties with its nuclear-armed neighbor. In recent years, Kim has prioritized relations with Russia, notably by sending troop s and military equipment to support Moscow’s war in Ukraine.

Xi’s trip was announced a day after North Korea unveiled what South Korea’s military assessed as a new uranium-enrichment facility for producing nuclear bomb fuel. During a visit to the unspecified site, Kim pledged to expand the country’s nuclear forces “at an exponential rate,” a move that experts say reflects his desire to cement North Korea’s status as a nuclear weapons state ahead of Xi’s visit.

Kang Kon is the second of two destroyers North Korea unveiled last year, following the Choe Hyon, whose development Kim hailed as a major step toward expanding the operational range and preemptive strike capabilities of his nuclear-armed military. State media said the ships are designed to carry a range of weapons systems, including anti-aircraft and anti-ship weapons as well as nuclear-capable ballistic and cruise missiles, though some experts have questioned their effectiveness in active duty.

Kang Kon was damaged during a botched launching ceremony in May last year at the northeastern port of Chongjin, triggering a furious reaction from Kim, who called the failure “criminal.” North Korea said Kang Kon was relaunched in June after repair, but outside experts have questioned whether the ship is fully operational. Kim has called for building two more 5,000-ton-class destroyers.