The Democratic People's Republic of Korea launched a ballistic missile, the South Korean military said on Thursday.

"North Korea fired an unidentified ballistic missile into the East Sea," Seoul's Joint Chiefs of Staff stated.

Japan also confirmed the firing of the missile saying the DPRK "launched a possible ballistic missile" as it called on vessels to take caution and not approach any unidentified objects in the sea.

Later, the Japanese parliamentary vice-minister of defense, Kimi Onoda, claimed that two ballistic missiles fell inside Japan's exclusive economic zone which extends 200 nautical miles past the Japanese coast. 

Relations between Pyongyang and Seoul are at one of their lowest points in years, as diplomacy has stalled and military activity has been expanded.

Missle launches in response to US aggression

The DPRK has launched a series of missiles this year, including test-firing powerful intercontinental ballistic missiles and deploying a satellite into orbit, in response to increased US military cooperation with Japan and South Korea.

The US and South Korea have been conducting provocative regular large-scale joint military drills, which currently include live-fire "annihilation" exercises. These exercises have greatly angered Pyongyang, as it views them as preparations for an invasion.

In a statement released by DPRK's Ministry of National Defense on Thursday, a spokesperson criticized the ongoing drills, accusing them of specifically targeting the DPRK with a massive mobilization of offensive weapons and equipment.

The drills hosted advanced weapons systems, including F-35A stealth aircraft, AH-64 Apache attack helicopters, K2 tanks, and Chunmoo multiple rocket launchers.

The statement warned that DPRK's armed forces would respond forcefully to any provocative actions or demonstrations by their enemies.

Furthermore, after the UN's condemnation of the latest satellite launch, an editorial by foreign affairs specialist Kim Myong Chol published in the state-run news agency suggested that the DPRK will no longer inform the International Maritime Organization of future launches.

"As IMO responded to the DPRK's advance notice on its satellite launch with the adoption of an anti-DPRK 'resolution', we will regard this as its official manifestation of stand that the DPRK's advance notice is no longer necessary. In the future, IMO should know and take measures by itself over the period of the DPRK's satellite launch and the impact point of its carrier and be prepared for taking full responsibility for all the consequences to be entailed from it," the commentary, titled "IMO Reduced into Tool for White House," read.