Takeshi Iwaya told local reporters that Tokyo believes the latest rockets launched by the Hermit Kingdom were a new short-range ballistic missile, pointing to the irregular trajectories they have taken, Reuters reported.
The warning came the same day three European nations – important allies to the United States – condemned the “repeated provocative launches” by the North, saying they violate U.N. Security Council resolutions banning such activity.
The U.K., France and Germany issued a joint statement urging Pyongyang “to engage in meaningful negotiations with the U.S.” and stressed that “international sanctions must remain in place and be fully and strictly enforced.”
“Serious efforts by North Korea to re-engage diplomatically and make progress to denuclearization are the only ways to guarantee security and stability on the Korean peninsula and in the region,” the statement said.
The governments that issued the statement not include the United States or other members of the 15-nation Security Council.
North Korea has launched seven short-range missiles into the Sea of Japan in the past month, sparking heightened tension in the region and with the United States.
Two of those tests came Saturday, a day after Seoul said it was ending a military intelligence-sharing pact with Tokyo, Reuters reported.
North Korea said Sunday that Kim Jong Un supervised the test-firing of a "newly developed super-large multiple rocket launcher."
President Trump responded to the launch saying, "Kim Jong Un has been, you know, pretty straight with me. … He likes testing missiles but we never restricted short-range missiles. We'll see what happens."
Negotiations between the U.S. and North Korea have been at a standstill since the second Trump-Kim summit in Hanoi in February broke down over what the United States described as excessive North Korean demands for sanctions relief in exchange for only a partial surrender of its nuclear capabilities.
Most of the North Korean weapons tested in recent weeks have shown short-range flight distances. This suggests that North Korea still doesn't intend to lift its self-imposed moratorium on nuclear and long-range missile tests, which would certainly derail negotiations with Washington.
The Associated Press contributed to this report.