Defying the United Nation's Security Council Resolutions, North Korea has fired their latest Submarine-Launched Ballistic Missile at around  5:30 a.m (4:30 p.m ET) about 500 km (311 miles) near the coastal city of Sinpo, Japan).  

According to Reuters, the said SLBM (Submarine-Launched Ballistic Missile) launched by North Korea has reached Japan's air defense identification zone, the area of control assigned by each country in order to maintain an air national security. Experts said that North Korea's efforts of improving the development of their missile system are now evident in the flight distance of their latest SLBM. 

ABC News reported that this missile launch happened two days after the annual military exercise of the United States and South Korea begun, the said military exercise is perceived by North Korea as a preparation for invasion. The presidential office of South Korea is said to discuss the missile event at 7:30am local time. it can be recalled that North Korea has been further isolated after their January nuclear test and their long-range rocket test held last February which both inflicted tightened UN sanctions. North Korea's missile tests this year also includes  a submarine missile last month which is said to have failed according to South Korea's military army. 

DailyMail reported that the current UN resolutions should prohibit North Korea from testing ballistic missile technology, much more should these tests be prevented to overlap other countries' air defense identification zones such as what happened now with Japan waters.

On the other hand, North Korea also claim to have a miniaturized nuclear warhead to fit on a ballistic missile, however, experts said that as of the moment  there is no evidence to back up that said claim. This recent missile event of North Korea has aggravated the tension between them and other UN countries.