North Korea launched a ballistic missile from its western region into the sea off its east coast on Tuesday, South Korea's military said, ahead of a summit of leaders from the Group of 20 countries in Germany later this week.

The missile flew for about 40 minutes and may have landed in Japan's Exclusive Economic Zone (EEZ), the Japanese government said, adding that it had strongly protested what was a clear violation of UN resolutions.

The missile was launched around 0040 GMT (8.40 p.m. ET) from an airfield in Panghyon, about 100 km (60 miles) northwest of the North's capital, Pyongyang, the South Korean military said.

The North's missile launch is the last since Pyongyang fired several cruise missiles in early June and comes ahead of the leaders of the United States, China, Japan and South Korea are expected to discuss efforts to rein in the North's nuclear and missile tests the G20 summit on July 7 to 8.

Pyongyang has been working to develop a nuclear-tipped missile capable of hitting the United States.

Earlier this week, North Korea was a key topic in phone calls between US President Donald Trump and the leaders of China and Japan. Leaders of both Asian countries reaffirmed their commitment to a denuclearised Korean Peninsula.

Tuesday's missile launch also comes ahead of July 4 Independence Day celebrations in the United States. North Korea has previously fired missiles around this US holiday.

South Korea's presidential Blue House said President Moon Jae-in called a national security council meeting for 0230 GMT after being informed of the North's missile launch.

Last week after his first summit with Moon, Trump called for a determined response to North Korea, stressing the importance of the alliance between the two countries.