North Korea has called the test of two new missiles on Thursday a “solemn warning” against what it described as “South Korean warmongers”.
The short-range missiles were fired into the Sea of Japan, also known as the East Sea, from Wonsan on North Korea’s east coast.
Leader Kim Jong-un said his country was forced to develop weapons to “eliminate potential and direct threats”.
He said the test involved a new tactical guided weapons system.
Mr Kim’s comments, reported in state media, come after the North criticised a decision by South Korea and the US to hold military drills next month.
North Korea has long regarded the drills as preparation for an invasion.
Though the US and South Korea have refused to cancel the annual military exercises, they have been scaled back significantly.
South Korea’s Joint Chiefs of Staff (JCS) said one of the new missiles travelled about 690km (428 miles). The US also confirmed that the missiles were “short-range”.
Mr Kim said he was “satisfied” with the new weapons system’s response and claimed it would “not be easy to defend against”.
He said that South Korea should “not make a mistake of ignoring the warning”.
South Korea has urged Pyongyang to stop acts that are unhelpful to easing tension and said the tests posed a military threat.
US Secretary of State Mike Pompeo downplayed concerns about the launch, however, calling them a negotiating tactic.
“Everybody tries to get ready for negotiations and create leverage and create risk for the other side, he told Bloomberg Television.
“We want diplomacy to work. If it takes another two weeks or four weeks, so be it.”