The launches also follow South Korea's announcement that it is quadrupling its reward for North Korean defectors who can provide them with classified military intelligence, raising the payment to 1 billion won ($860,000), CNN reported Sunday.
Shortly after the order was given, North Korea's missiles began exploding on launch, straying from their intended flight paths, or coming apart mid-flight.
North Korea last fired a ballistic missile on February 12, drawing condemnation from the U.N Security Council.
By targeting Japan's exclusive economic zone with the missiles fired Monday, Pyongyang suggests that it also eyes USA military bases in Japan, which would provide reinforcements in the event of hostilities on the Korean Peninsula.
Weapons experts say solid-fuel missiles pose greater threats as they require less launch preparation time than liquid-fueled rockets, and can be fired from mobile launchers, which are easy to move around.
The other four landed in the sea, the official said. "It was the timing that was important, not the scientific novelty", he said, adding that the tests came as Washington and Seoul were conducting annual joint military exercises. "It is direct challenge to the globe and serious provocation", said Hwang in opening remarks.
In his New Year address, North Korean leader Kim Jong-un said his nation was nearly ready to test-fire an intercontinental ballistic missile.
In Washington, the State Department strongly condemned the launches, saying the U.S. was ready to "use the full range of capabilities at our disposal against this growing threat". "The DPRK's provocations only serve to increase the worldwide community's resolve to counter the DPRK's prohibited weapons of mass destruction programs", acting State Department spokesman Mark Toner said in a statement.
No reason to stop Dalai Lama's visit, says Kiren Rijiju
Dalai Lama is considered by China as a risky separatist leader, who can affect for the worse ties between India and China. China had already warned India that any understanding with the Tibetan spiritual leader could damage the bilateral ties.
European Union foreign affairs chief Federica Mogherini said launches were "in utter disregard" of several United Nations resolutions and further raised tension in the region.
The European Union has also condemned North Korea for firing the four banned ballistic missiles and said it would consult with Japan and global partners on how to react.
Seoul and Washington launched the annual Foal Eagle exercises last week, with the North's military warning a day later of "merciless nuclear counter-action" against enemy forces.
Mark Fitzpatrick says the timing of today's test was political in nature, primarily as a defiant response to the military exercise at North Korea's border.
The US military said after it'd found and monitored a launching but had discovered that it didn't present a danger to North America. A spokesperson for the Foreign Ministry in Pyongyang on Saturday labeled the troops as aggressors and warned that even a minor incident would be met with stern retribution.
The United States, Japan and South Korea strongly condemned the launches - the second in three weeks. "I look forward to seeing immediate and determined actions from the Trump Administration and will be asking for a full briefing outlining the actions it will take to stop the madman in Pyongyang".
Kremlin spokesman Dmitry Peskov said Moscow is seriously anxious about the missile drills.