North Korea fired a long-range ballistic missile into the East Sea on Saturday, according to South Korea's military.

The North's second ballistic missile provocation this year came as the South and the United States plan to hold a joint military training next week against Pyongyang's potential use of nuclear weapons.

The Joint Chiefs of Staff said it detected the launch from the Sunan area in Pyongyang at 5:22 p.m. and that the missile, fired at a lofted angle, flew some 900 kilometers.

It did not give other details, saying the intelligence authorities of the South and the United States are conducting a detailed analysis on the missile's specifics.

The North previously fired an intercontinental ballistic missile in November last year.

"The North's long-range ballistic missile launch this time is an act of significant provocation that harms peace and stability not only on the Korean Peninsula but also in the international community," the JCS said in a text message sent to reporters

It also called the launch a "clear" violation of UN Security Council resolutions and urged the North to immediately stop such a provocative act.

"While tracking and monitoring related movements in close cooperation with the US in preparation against the possibility of additional provocations, our military will maintain a firm readiness posture capable of responding overwhelmingly to any North Korean provocations," the JCS said.

The North's foreign ministry stated Friday that the country will take "unprecedentedly persistent and strong" counteractions should the allies press ahead with their plans to stage combined military drills.

They are scheduled to conduct a table-top exercise at the Pentagon next week under the scenario of nuclear use by the North. They are also scheduled to hold the regular springtime Freedom Shield exercise next month.

The FS exercise is set to take place alongside concurrent large-scale field drills in line with the allies' push to strengthen the scope and scale of their joint military exercises.

With the latest missile launch, some observers here said, the North might be protesting at the South's labeling of its regime and military as an "enemy" in its updated defense white paper made public earlier this week.

North Korea held a military parade last week to mark the 75th founding anniversary of its army, displaying the largest number of Hwasong-17 ICBMs and what was presumed to be a solid-fuel ICBM. The regime described the ICBMs on display as demonstrating its "maximum nuclear attack capabilities."

South Korea's presidential National Security Council held a meeting after the North's long-range missile launch. The NSC standing members "strongly" condemned North Korea's latest missile firing, vowing stern measures against any attempt by the North to threaten the South.

In a statement, the U.S. Indo-Pacific Command also denounced the North's provocation and called on it to refrain from any further "unlawful and destabilizing acts."

The North fired around 70 ballistic missiles, including eight ICBMs, last year alone, the most in a single year.

At a key party meeting late last year, North Korean leader Kim Jong-un called for an "exponential" increase in its nuclear arsenal, raising the need to mass-produce tactical nuclear weapons apparently targeting the South and to develop a new ICBM. (Yonhap)