North Korean leader Kim Jong-un has reportedly overseen a test of strategic cruise missiles aboard a Navy warship in apparent response to the start of a combined military exercise between South Korea and the U.S.

The North’s official Korean Central News Agency(KCNA) reported on Monday that Kim inspected the Guards Second Surface Ship Flotilla of the East Sea Fleet of the Navy of the Korean People's Army, without specifying the date of the inspection.

Kim also observed a strategic cruise missile launching drill conducted by the ship the same day.

The KCNA said the launch was aimed at verifying the combat function and missile systems of the vessel, while improving the sailors' capability to carry out an attack mission in actual war, adding that the ship rapidly hit targets without any errors.

Kim reportedly stressed the importance of the mission and duty of the Navy to destroy the enemy’s will to fight in case of an emergency, carry out the strategic and tactical intentions of the supreme military command, and defend the regime’s sovereignty and security.

Kim also called for stepped-up efforts to improve the Navy's combat power and modernize naval armament.

South Korea and the U.S. kicked off the combined Ulchi Freedom Shield exercises on Monday.