North Korea fired a missile off its eastern coast on Tuesday.
That's according to South Korea's military and Japan's defense ministry said it appeared to be a ballistic missile, but gave no further details.
The announcement came just before North Korea's ambassador to the United Nations, Kim Song, urged the U.S to give up its hostile policy towards Pyongyang.
"We are just building up our national defense in order to defend ourselves and reliably safeguard the security and peace of the country."
North Korea has accused Seoul and Washington of "double standards," saying they denounced its weapons development while continuing their own military activities.
The North and South have been developing increasingly sophisticated weapons and back in September, both test fired ballistic missiles.
Washington condemned the North's September test and a separate launch days earlier.
Experts said that may have been its first cruise missile capable of carrying a nuclear warhead, a threat to its neighbors.
At the time, Washington did not mention Seoul's test of a submarine-launched ballistic missile also fired in September.
In a statement on Monday, the U.S military said the latest missile launch posed no immediate threat to U.S. personnel or territory, or U.S. allies.