Three North Korean short-range ballistic missiles have failed, the US military said, in a temporary blow to Pyongyang's rapid nuclear and missile expansion.
The US Pacific Command said two of the North's missiles failed in flight after an unspecified distance on Saturday and another appeared to have blown up immediately.
It added that the missile posed no threat to the US territory of Guam, the direction where the North previously warned it would aim missiles.
South Korea's Joint Chiefs of Staff said the missiles fired from the North's eastern coast flew about 155 miles, though it did not mention any failures.
It said the South Korea and US military were analysing the launch.
Seoul's presidential office held a National Security Council meeting to discuss the missiles, the first known launches since July, when the North successfully flight tested a pair of intercontinental ballistic missiles that analysts say could reach deep into the US mainland when perfected.
The rival Koreas recently saw their always-testy relationship get worse after Pyongyang and US president Donald Trump traded warlike threats.
Mr Trump warned he would unleash "fire and fury" if the North continued its provocation.
The latest launch comes during an annual joint military exercise between the United States and South Korea that the North says is an invasion rehearsal, and weeks after Pyongyang threatened to lob missiles towards Guam.
North Korea's state media earlier said leader Kim Jong Un inspected a special operation forces training of the country's army that simulated attacks on South Korean islands along the countries' western sea border, in what appeared to be in response to the ongoing US-South Korea war games.
Kim reportedly told his troops that they "should think of mercilessly wiping out the enemy with arms only and occupying Seoul at one go and the southern half of Korea".
The Korean Central News Agency said that the "target striking contest" involved warplanes, multiple-rocket launchers and self-propelled guns that attacked targets meant to represent South Korea's Baengnyeong and Yeonpyeong islands before special operation combatants "landed by surprise" on rubber boats.
The border islands have occasionally seen military skirmishes between the rivals, including a North Korean artillery barrage on Yeonpyeong in 2010 that left two South Korean marines and two civilians dead.
The White House said Mr Trump was briefed on the latest North Korean activity and "we are monitoring the situation".
South Korea's presidential office said US and South Korean forces would proceed with their war games "even more thoroughly" in response to the missile launches.
The Blue House issued the statement after national security director Chung Eui-yong chaired a National Security Council meeting to assess the launches.