People watching a TV screen picturing footage of a North Korean missile test, at a railway station in Seoul on Sunday (AFP)

North Korea has launched a short-range ballistic missile into the Sea of Japan, according to South Korean news agency Yonhap, citing the Joint Chiefs of Staff (JCS).

The South Korean military recently detected suspected indicators of preparations for the launch of a submarine-launched ballistic missile (SLBM) near the North Korean city of Sinpo, according to the news agency.

The North Korean missile flew approximately 372 miles at a maximum height of 37 miles at a speed of roughly Mach 5. Details are being evaluated by South Korean and US spy services, according to JCS.

The missile was launched as the USS Ronald Reagan carrier strike group arrived in the port of the South Korean city of Busan to participate in combined drills with the South Korean navy, according to the news agency, which added that the drills will take place in the Sea of Japan later this month.

Later, the Japanese government protested through diplomatic channels to North Korea over the missile launch.

"North Korea's missile launch amid the ongoing situation in Ukraine is absolutely inexcusable. This is a violation of the provisions of the UN Security Council resolutions. We strongly condemn these actions and send our protest to North Korea through diplomatic channels in Beijing," Japanese Defense Minister Yasukazu Hamada said at a press conference.

North Korea's missile went 248 miles with a maximum altitude of 31 miles and landed beyond the exclusive economic zone, according to Hamada. To collect and evaluate information in connection with the missile launch, an emergency headquarters was established at the office of Japanese Prime Minister Fumio Kishida.

A senior US official warned, a few days ago, that North Korea "may conduct a nuclear test," during US Vice President Kamala Harris' visit to Japan and South Korea.

North Korea has declared itself, at the legislative level, a nuclear state, giving North Korean President Kim Jong Un the "right to act with nuclear weapons."

Moreover, the US strategy toward North Korea has not changed since the latter declared itself a nuclear weapons state, and Washington will continue to seek a diplomatic solution to achieve the goal of demilitarizing the Korean Peninsula, claimed White House Spokesperson Karine Jean-Pierre.