South Korea's Joint Chiefs of Staff says North Korea fired off a ballistic missile into the East Sea Tuesday morning.

The projectile was launched around 10:20 a.m. from the port city of Sinpo in South Hamgyong Province, according to the JCS.

It did not say what kind of ballistic missile was fired, but it could have been launched from a submarine as Sinpo is a major naval shipyard.

This latest test marks the seventh show of force by Pyongyang this year, in defiance of U.N. resolutions that ban the North from engaging in ballistic missile activities.

It comes amid apparently improving inter-Korean relations, while dialogue between the regime and the United States remain strained despite Washington's stance that it remains willing to talk anytime, anywhere without preconditions.

South Korea's presidential office said it was opening a meeting of its National Security Council in response to the North's latest launch.