Japanese Prime Minister Shinzo Abe on Friday said that if the Democratic People's Republic of Korea (DPRK) has conducted a nuclear test as believed due to the detection of an artificial earthquake, then it was unacceptable and would be protested.
"If North Korea has conducted a nuclear test, it is simply unacceptable. We must strongly protest against it," the prime minister said.
Abe also said that Japan would liaise closely on the matter with the United States and South Korea as the situation unfolds.
The Japanese leader also said he had instructed all relevant officials in his office and applicable ministries to gather more information about the possibility the DPRK had tested a nuclear device.
The prime minister's instructions follow Japan's Meteorological Agency (JMA) detecting an artificial earthquake centered in the DPRK close to a previous test site, which it believes may have been a nuclear test.
The weather agency here said the depth of the artificial earthquake was at 0 kilometers, which is consistent with previous nuclear tests conducted by the DPRK.
In a hastily convened press conference, Chief Cabinet Secretary Yoshihide Suga said earlier on Friday that the government here is currently gathering more information about the possible nuclear test by the DPRK.
"Given similar cases in the past, we think an earthquake detected in the morning may have been a nuclear test by North Korea," Japan's top government spokesman said, adding that Japan will cooperate with relevant countries to gather and analyze more information regarding the DPRK's possible testing of a nuclear device.
Foreign Minister Fumio Kishida also said that Japan would convene an emergency meeting of its National Security Council (NSC) to discuss issues relevant to the incident.
Government officials here have also said that if the test is confirmed, it will call for an emergency UN Security Council meeting on the matter.
The DPRK is banned by UN sanctions from any tests of nuclear or missile technology.
The DPRK conducted a fourth nuclear test in January this year.
