North Korea fired what appeared to be a "submarine-launched ballistic missile", Seoul said Wednesday, a day after Washington and Pyongyang announced they would resume stalled nuclear talks.

Pyongyang frequently couples diplomatic overtures with military moves, as a way of maintaining pressure on negotiating partners, analysts say, and may believe this weapons system gives it added leverage.

A proven submarine-based missile capability would take the North's arsenal to a new level, allowing deployment far beyond the Korean peninsula and a "second-strike" capability in the event of an attack on its military bases.

The South's Joint Chiefs of Staff said it detected a ballistic missile early Wednesday fired around 450 kilometres (280 miles) in an easterly direction at a maximum altitude of 910 kilometres.

The missile was "believed to be one of the Pukkuksong models", the JCS said in a statement, referring to a line of submarine-launched ballistic missiles (SLBM) under development by the North.

"Such actions by North Korea to raise tensions are not helpful to efforts to ease tensions on the Korean peninsula and we urge it again to stop immediately," it added.

The North carried out a successful test of the Pukkuksong-1, also known as KN-11, in August 2016 which flew around 500 kilometres.

The United States said it was monitoring the situation on the Korean peninsula.

One of the projectiles fell into waters within Japan's exclusive economic zone -- a 200-kilometre band around Japanese territory -- Tokyo said.

"The launching of ballistic missiles violates UN Security Council resolutions and we strongly protest and strongly condemn it," Prime Minister Shinzo Abe told reporters.

The North is banned from ballistic missile launches under UN Security Council resolutions.

- 'Negotiating position' -

The launch came a day after the North's Vice Foreign Minister Choe Son Hui said Pyongyang had agreed to hold working-level talks with Washington later this week.

The two sides will have "preliminary contact" on Friday and hold negotiations the following day, Choe said in a statement carried by the official Korean Central News Agency.

US State Department spokeswoman Morgan Ortagus later confirmed the talks, which she said would happen "within the next week".

Source: National News Agency