But North Korea has said its missile testing is in reaction to threats against it by the South, the US and Japan.
"North Korea fired an unidentified projectile at Pukchang, South Pyongan province in the afternoon today", the South's Joint Chiefs of Staff said in a statement.
According to the JCS officials, the projectile flew some 500 kilometers, and the South Korean and the USA militaries are analyzing its details including the type and its exact trajectory.
The missile was launched Sunday at about 4:59 p.m. Seoul time from a site in the vicinity of Puckchang county, which is home to North Korea's largest power plant.
In Tokyo, Japanese Prime Minister Shinzo Abe called the launch a "challenge to the world" that tramples global efforts to resolve the North Korean nuclear and missile problems peacefully.
"If you are a country that is supplying or supporting North Korea, we will call you out on it", Haley said. He vowed to bring up the issue at this week's G-7 summit in Italy.More news: Cannes apologizes for projection snafu with Netflix's 'Okja'
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This system was last tested in February, the official noted, adding that it has a shorter range than the missiles launched in North Korea's three most recent tests.
However, it still remains unclear whether the missile can carry a heavy nuclear warhead.
North Korea conducted two nuclear tests previous year alone, possibly improving its ability to make nuclear weapons small enough to fit on long-range missiles.
We are working with our Interagency partners on a more detailed assessment. If the North ever obtains a solid-fuel ICBM, it would likely be a rocket powered by a cluster of several Pukguksong-2 engines, Kim said.
It's the second from North Korea since South Korean President Moon Jae-in took office earlier this month. The newspaper likened the USA aircraft carrier to a "gross animal" and said a strike on the carrier would be "an actual example to show our military's force".
"Our military is closely monitoring North Korea and is maintaining readiness posture", the statement said.