Defense Minister Gen Nakatani said Friday that the missile launched by North Korea earlier in the day had no impact on the security of Japan.

The launch was widely reported to have failed, with defense officials in Washington quoted saying the rocket probably exploded.

"We have not confirmed any projectile heading toward our country. No event or circumstance influencing our security has occurred," Nakatani told reporters.

"The Defense Ministry is collecting and analyzing information at all times. We've gathered information on this case as well, but I will refrain from commenting on this, considering the nature of the matter."

South Korea's Joint Chiefs of Staff said North Korea fired a missile from its east coast in the early hours of Friday, a public holiday that marks the birthday of the late founder and leader of North Korea, Kim Il Sung.

A South Korean military source said the projectile appeared to be an intermediate-range Musudan missile, with a reported range of 4,000 km. This gives it the potential to strike any city in Japan.

"Japan is analyzing and collecting information in coordination with the United States and South Korea. The Self-Defense Forces have also taken necessary preparations," Chief Cabinet Secretary Yoshihide Suga said. He stopped short of confirming that the launch took place.

Foreign Minister Fumio Kishida said he will coordinate with the United States and South Korea in urging Pyongyang to exercise restraint.

"North Korea's provocative acts, in any form, are unacceptable," he told reporters.