South Korea’s military said it detected North Korea firing multiple cruise missiles into waters off its western coast on Friday.

The launches came hours after state media reported that North Korean leader Kim Jong Un reiterated his focus on strengthening his naval forces as he inspected the construction of new warships at a western shipyard, calling such projects crucial to the country’s war preparations.

South Korea’s Joint Chiefs of Staff said the US and South Korean militaries were analysing the launches, which were the North’s fourth round of cruise missile tests in 2024.

Mr Kim’s visit to the shipyard in Nampho followed a series of weapons demonstrations in January that further increased tensions with rivals, including tests of new cruise missiles designed to be launched from submarines.

In recent months, the North Korean leader has been emphasising his goals of building a nuclear-armed navy to counter what he portrays as growing external threats posed by the US, South Korea and Japan, which have stepped up their military cooperation to cope with Mr Kim’s nuclear weapons and missile programme.

North Korea’s official Korean Central News Agency (KCNA) did not specify when Mr Kim visited Nampho, paraphrasing him as saying the strengthening of his naval force “presents itself as the most important issue in reliably defending the maritime sovereignty of the country and stepping up the war preparations”.

KCNA did not specify the types of warships being built in Nampho, but said they were related to a five-year military development plan set during a ruling party congress in early 2021.

During the inspection, Mr Kim was briefed on the progress of his naval projects and remaining technological challenges and ordered workers to “unconditionally” complete the efforts within the timeframe of the plan that runs through 2025, KCNA said.

Kim Inae, spokesperson of South Korea’s Unification Ministry, said it was likely the first time state media had reported the North Korean leader giving a military-related inspection in Nampho, as the country’s eastern shipyard of Sinpo had been its main hub building advanced naval vessels like submarines.

She said: “By making military threats routine, North Korea is trying to create a sense of insecurity among South Korean people to undermine trust in their government and to attract international attention to build an atmosphere in which its demands must be accepted to resolve the crisis on the Korean Peninsula.”

Mr Kim also called for naval might on Sunday while inspecting a test of a new nuclear-capable cruise missile, the Pulhwasal-3-31, designed to be fired from submarines.