This photo, carried by North Korea's official Korean Central News Agency on Jan. 25, shows the North's first test-firing of new Pulhwasal-3-31 strategic cruise missiles the previous day. Yonhap

North Korea said Thursday it test-fired a new strategic cruise missile, named "Pulhwasal-3-31," for the first time the previous day in what was seen as an effort to strengthen capabilities to deliver nuclear weapons.

The North's Missile General Bureau said the test-fire is a "process of constant updating of the weapon system and a regular and obligatory activity of the agency and its affiliated defense science institutes," according to the Korean Central News Agency (KCNA).

The report did not provide details, such as how far the missile flew.

South Korea's military had said Wednesday the North fired several cruise missiles toward the Yellow Sea at 7 a.m., but gave no further details, including the distances they flew.

It marked the North's first known cruise missile launch since September last year, when the country launched two long-range strategic cruise missiles with mock nuclear warheads toward the Yellow Sea. At that time, Pyongyang said the missiles traveled 1,500-kilometer-long eight-shaped flight orbits.

The North's leader Kim Jong-un, center, at a key munitions factory during an inspection tour on Jan. 8-9, calling South Korea the North's "principle enemy," in this photo carried by North Korea's official Korean Central News Agency, Jan. 10. Yonhap

The North first test-fired the Hwasal-1 cruise missile in September 2021 and launched several Hwasal-1 and -2 cruise missiles presumed to be capable of carrying tactical nuclear weapons last year.

Hwasal means an arrow in Korean, and Pulhwasal means a fire arrow.

Cruise missiles fly low and maneuver, making them better at evading missile defenses.

The South Korean military said the North's latest launch appears to be aimed at upgrading the capability of the existing cruise missiles, but did not provide further details.

"The flight distance of North Korea's cruise missiles fired the previous day was shorter compared with previous launches," Col. Lee Sung-jun, spokesperson of the Joint Chiefs of Staff, said in a regular press briefing.

"We detected and tracked the cruise missile launched by North Korea in real-time. It disappeared at the final stage, and further analysis is needed to determine the circumstances surrounding that," he said.

Experts said the Pulhwasal-3-31 is seen as a nuclear-capable weapon, considering that the number in its name is identical to that of the Hwasan-31, a tactical nuclear warhead that North Korea first unveiled in March 2023.

"The number 31 is presumed to be hinting at the power of North Korea's tactical nuclear warhead under development," said Chang Young-keun, head of the missile center at the Korea Research Institute for National Strategy.

The launch of a cruise missile is not a direct violation of multiple United Nations Security Council resolutions banning the North's use of ballistic missile technology. But it could pose a serious threat to South Korea's security as nuclear warheads can be mounted on such missiles.

North Korean leader Kim Jong-un has called for an "exponential" increase in the country's nuclear arsenal and the development of tactical nuclear weapons against South Korea.

The latest provocation came after North Korea launched a solid-fuel hypersonic missile into the East Sea on Jan. 14 in its first missile firing this year.

Pyongyang also claimed last week it had tested an underwater nuclear attack drone in protest of the latest joint military drills among South Korea, the United States and Japan.

North Korea has dialed up tensions on the Korean Peninsula with weapons tests and hard-worded rhetoric in an election year for South Korea and the U.S.

During a year-end party meeting, Kim Jong-un defined inter-Korean ties as relations between "two states hostile to each other" and vowed to "suppress" the whole territory of South Korea in the event of a contingency.

At a key parliamentary meeting last week, Kim called for revising the country's constitution to define South Korea as the North's "primary foe" and announced the country will abandon its decadeslong policy of seeking reconciliation and unification with the South. (Yonhap)