South Korea's military says Sunday's missile launch by North Korea could have been provoked by joint drills it plans to hold with the US.

South Korean military officials announced that North Korea launched a short-range ballistic missile toward the Sea of Japan at around 6:53 AM Sunday.

The officials say the missile was fired from near the Taechon area of North Phyongan Province in the country's northwest.

They say the missile traveled about 600 kilometers, reaching an altitude of about 60 kilometers, at a maximum speed of about Mach 5.

Japanese Defense Minister Hamada Yasukazu said it can be presumed that the missile landed outside Japan's Exclusive Economic Zone.

Hamada also said the missile could have been a model capable of following irregular flight paths.

He said there have been no reports so far of damage to Japanese ships or aircraft.

Hamada said "We strongly condemn the launch. It violates Security Council resolutions."

North Korea fired a total of eight ballistic missiles in June alone. Sunday's launch was the 19th this year.

South Korea's presidential office has expressed concerns, as it was the first launch since Pyongyang adopted a nuclear policy early this month.

The law outlines conditions under which the country would launch a nuclear strike, enshrining the right to use nuclear weapons.

And North Korea has been on edge over US-South Korea joint drills scheduled to take place soon around the Sea of Japan.

The US nuclear-powered aircraft carrier Ronald Reagan docked in the southeastern city of Busan on Friday ahead of the drills.

South Korean and US military forces have been on high alert, as there are signs that Pyongyang may be preparing to launch a ballistic missile from a submarine.