"Conducting missile tests is an inalienable and sovereign right of the People's Democratic Republic of Korea, and nobody has the right to tell us whether we can do it or not," a spokesman for the Foreign Ministry told a news conference in Pyongyang, adding that the ministry could not provide detailed information on the tests.
The communist nation launched the missiles, including a long-range Taepodong-2, late Tuesday despite a moratorium on missile tests. According to the Japanese military, all the missiles fell into the northwest of the Sea of Japan.
North Korea agreed with Japan to a moratorium on missile tests in 2002, but the secretive regime has continued research on ballistic missile technology.
North Korea last tested a long-range missile was in 1998, when it launched a Taepodong-1 over northern Japan, which, as it is in easy reach of a long-range missile from North Korea, strongly condemned the missile tests on Wednesday.
Chief Cabinet Secretary Shinzo Abe said the tests represented a serious problem for peace and stability not only for Japan but also for international society.
The Japanese official also said the country was considering urgent measures in accordance with international law, including economic sanctions, against North Korea. Tokyo has already announced a ban on visits by North Korean ferries.
Japan earlier said it was coordinating its response to the missile tests with the U.S. and other countries and requested a closed session of the UN Security Council to discuss the developments.
