North Korean missile test fails after show of military strength
A North Korean medium-range missile exploded seconds after it was launched on Sunday, US officials said.
The high-profile failure came hours before US vice president Mike Pence arrived in South Korea, and as an American aircraft supercarrier approaches the Korean Peninsula in a show of force.
The US had good intelligence both before and after the launch, said a White House foreign policy adviser travelling with Mr Pence, who arrived in Seoul to start a 10-day trip to Asia.
No planned response is expected from the Trump administration because the official said there was no need for the US to reinforce the failure.
The official said that had it been a nuclear test "other actions would have been taken by the US".
North Korea has conducted five nuclear tests, including two last year. Recent satellite imagery suggests the country could conduct another underground nuclear test at any time.
The White House believes the latest test involved a medium-range ballistic missile that failed within 4-5 seconds after launch, and that it did not involve an intercontinental ballistic missile, the adviser said.
The North regularly launches short-range missiles, but is also developing mid-range and long-range missiles meant to target US troops in Asia and, eventually, the US mainland.
The failed launch will sting in Pyongyang because it came a day after one of the biggest North Korean propaganda events of the year - celebrations of the 105th birthday of late North Korea founder Kim Il Sung, the current leader's grandfather.
President Donald Trump was uncharacteristically quiet about the failed launch, which was attempted from the east coast city of Sinpo.
In a statement, Defence Secretary Jim Mattis said Mr Trump and his military team "are aware of North Korea's most recent unsuccessful missile launch. The president has no further comment".
North Korea's ultimate goal is to have a full array of nuclear-tipped missiles in response to what Pyongyang says is hostility by Washington and Seoul meant to topple its government. North Korea is thought to have a small arsenal of atomic bombs and an impressive array of short- and medium-range missiles.
Many outside analysts believe that North Korea has not yet mastered the technology to build warheads small enough to place on long-range missiles, though some civilian experts say it can already build nuclear-tipped shorter range missiles that have South Korea and Japan within its striking range.
The US Pacific Command said the missile exploded on launch. South Korea's Defence Ministry said it was analysing exactly how the North Korean launch failed.
In Seoul, South Korea's presidential office convened a national security council meeting to examine security postures.
Kim has overseen three nuclear tests and a string of missile and rocket launches since taking over after the death of his father, dictator Kim Jong Il, in late 2011.
Another missile test from Sinpo failed earlier this month, when the rocket spun out of control and plunged into the ocean. That launch came shortly before Mr Trump's first meeting with Chinese leader Xi Jinping. China is North Korea's only major ally.
Washington sees North Korea's pursuit of nuclear weapons and ballistic missiles as a threat to world security and to its Asian allies, Japan and South Korea.
The US, South Korea and other countries have vowed to apply more pressure on the North, but so far nothing has worked to stop Pyongyang's nuclear program.
Six-nation negotiations on dismantling North Korea's nuclear program in exchange for aid fell apart in early 2009.