The North attempted but failed to test-launch ballistic missiles four consecutive times in the past two months but has conducted a variety of missile testing since the beginning of last year at an unprecedented pace.
Weapons experts and government officials believe the North has accomplished some technical progress with those tests.
U.S. President Donald Trump warned in an interview with Reuters in late April that a "major, major conflict" with the North was possible, but he would prefer a diplomatic outcome to the dispute over its nuclear and missile programmes. The reported launch is the first since a new liberal president took office in South Korea on Wednesday saying dialogue as well as pressure must be used to ease tensions on the Korean peninsula and stop the North's weapons pursuit. It comes after North Korea demanded the US and South Korea hand over "terror suspects" who it claims plotted to kill Kim Jong Un with a biochemical substance.
The secretive country last week claimed the CIA had sent a lumberjack to kill the dictator during the Day of the Sun celebrations in Pyongyang in April. The alleged plot involved "biochemical substances" such as radioactive substances or nano poisonous substances, the country claimed. Earlier this week, North Korean vice foreign minister Han Song Ryol told foreign diplomats and reporters that it would hunt down the suspects.
"The Central Prosecutor's Office will ask for the handover of those criminals and prosecute them under the relevant laws,"he said. The CIA and the U.S. White House declined to comment on the statement from the North's Ministry of State Security last week. The South Korean intelligence service said the charge was "groundless". Han "declared the principled stand of the ... government to find out all of the terrorist maniacs and mercilessly wipe them out", the North's KCNA news agency said in a report on the briefing.
There was no elaboration in either the Xinhua report or the KCNA report on how many suspects North Korea was seeking, or of who or where they were, but Xinhua said North Korea had vowed to "hunt down to the last one of the suspects in every corner of the earth". Separately, the CIA said on Wednesday it had established a Korea Mission Center to "harness the full resources, capabilities and authorities of the Agency in addressing the nuclear and ballistic missile threat posed by North Korea".
The center would gather experienced officers from across the CIA in one entity "to bring their expertise and creativity to bear against the North Korea target", it said.