which can reach the United States.
"It sounds like a field exercise involving deployed missiles, probably ones we've seen before Joshua Pollack, editor of the U.S.-based Non-Proliferation Review said.
South Korea's acting president Hwang Kyo-ahn strongly condemned the North's actions.
"This is a direct challenge to the international community and a grave violation," he said.
"Having seen the brutality of North Korea from Kim Jong Nam, I'd say the consequences of the Kim Jong Un regime having nuclear weapons will be horrible," he said referring to the killing of the North Korean leader's estranged half brother at Kuala Lumpur airport in February.
Acting spokesperson for the U.S. State Department, Mark Toner also slammed the move and said it remained "prepared to use the full range of capabilities at our disposal against this growing threat."
"The DPRK's provocations only serve to increase the international community's resolve to counter the DPRK's prohibited weapons of mass destruction programs," Toner said in a statement.
South Korean and Japanese officials said the missile tests are likely a reaction to huge joint military naval exercises by Washington and Seoul that Pyongyang insists are an invasion rehearsal.
North Korea, which has been at odds with the United States since the start of the Korean War in 1950, first tested a nuclear weapon in 2006.
Tensions in the Korean Peninsula escalated after North conducted its fourth nuclear test in January 2016, followed by a satellite launch in February.
The tests irked the international community and provoked the ire of the United Nations, that imposed several sanctions of the reclusive nation.
The country claimed to have secured key intercontinental ballistic missile technologies and eight months after the first test, shocked the world by conducting its fifth nuclear test overall and the strongest one till date.
Apart from the two provocative nuclear tests, in 2016, the isolated country test fired the Musudan missiles over 20 times.
The Musudan missile, with a design range of 1,500 to 2,500 miles, is believed to be capable of reaching South Korea, Japan and even the U.S. territory of Guam and almost reaching Alaska.
In his New Year's speech, the country's dictator Kim Jong Un declared that North Korea has "reached the final stage" in its program to build ICBMs (Inter-Continental Ballistic Missile), but western experts were skeptical about his forecast.
Earlier last month, in a similar move, North Korea fired a ballistic missile into the Sea of Japan - in what became the first provocation from the elusive nation since Donald Trump’s shock victory in the November 2016 U.S. Presidential elections.
The launch of the missile came a day after Trump held a very warm meeting with Japanese Prime Minister Shinzo Abe and reiterated America’s long-standing security alliance with Japan