Japan said on Monday it is preparing for North Korea to launch in the coming weeks what Pyongyang has described as a satellite, but Tokyo believes may be a ballistic missile.

Pyongyang has informed Japan's coastguard that a rocket will be launched between May 31 and June 11 and will fall in waters near the Yellow Sea, East China Sea and east of Luzon Island in the Philippines, a coastguard spokesman said.

However, the prime minister's office in a tweet said Fumio Kishida issued instructions "on North Korea's notification about the launch of a ballistic missile that it describes as a satellite".

He has told officials to gather intelligence, remain vigilant and closely coordinate with allies, including the United States and South Korea, the tweet added.

And Japan's defence ministry has issued an order for the Air Self-Defense Force to destroy any ballistic missile confirmed to be on course to fall into the country's territory.

The troops would be authorised to use Standard Missile SM-3 and Patriot Missile PAC-3 to shoot down a projectile in mid-air, the ministry said.

"Even if it's described as a satellite, a launch using ballistic missile technology would be a violation of United Nations Security Council resolutions and a serious problem that threatens the safety of people," Kishida told reporters.

Pyongyang has intensified its missile launches in recent months, with some triggering emergency warning systems in parts of Japan.

Seoul and Tokyo have meanwhile been working to mend long-frayed ties, including with greater cooperation on North Korea's military threats.

Asked about possible negotiations with North Korea leader Kim Jong Un, Kishida on Monday reiterated that Tokyo is open to talks, adding he was interested in "making concrete progress".

North Korean state media meanwhile published a statement from its vice-minister of foreign affairs, appearing to endorse a conciliatory approach to relations with Japan.

If Japan avoids "being shackled by the past, and seeks a way out for improving the relations, there is no reason for the DPRK and Japan not to meet", the statement from Pak Sang Gil said. (AFP)