North Korea has attempted to launch a missile on its east coastwhich is believed to have failed, South Korean and US military officials say.
The US said it had detected a ballistic missile, which blew up immediately.
It comes a day after North Korea warned the US that it was "ready to hit back with nuclear attacks" amid mounting tension in the region.
The state has already conducted five nuclear tests and a series of missile launches.
Meanwhile, US Vice-President Mike Pence is flying to the South Korean capital, Seoul, where he is expected to discuss the best way to deal with North Korea's missile and nuclear programmes.
Souece BBC News.