The missile was launched on Wednesday from near the capital, Pyongyang, South Korea's Joint Chiefs of Staff said.
Japan's defence ministry said the missile flew to an altitude of about 100km and range of more than 200km.
Senior officials of South Korea, the United States and Japan held a phone call and condemned the launch as a violation of multiple UN Security Council resolutions and a serious threat to the peace and stability of the region and beyond.
South Korean and US air forces said they conducted joint exercises involving F-22 and F-35 stealth fighter as part of their annual Buddy Squadron training.
South Korea's marine corps staged separate firing drills near the maritime border with the North for the first time since Seoul scrapped an inter-Korean military pact early in June.
The drills were announced earlier in June.
US Indo-Pacific Command also issued a condemnation and called on Pyongyang to refrain from further unlawful and destabilising acts.
"While we have assessed that this event does not pose an immediate threat to US personnel, or territory, or to our allies, we continue to monitor the situation," it said in a statement.
North Korea's last missile launch was on May 30.
North Korea this week criticised the deployment of a US aircraft carrier to joint drills with South Korea and Japan, and warned of an "overwhelming, new demonstration of deterrence".
The missile launch comes a day after the 74-year anniversary of the beginning of the Korean War.
Last week, North Korean leader Kim Jong-un and Russian President Vladimir Putin held a summit and signed a mutual defence pact.Â
Seoul, Washington and Tokyo criticised the two countries' deepening military co-operation, with South Korean President Yoon Suk-yeol calling the pact "anachronistic".
North Korean state media KCNA said on Wednesday a mass rally in Pyongyang was held to commemorate the war anniversary, calling it a day of "struggle against US imperialism" and calling the United States the archenemy.
Recently, North Korea has flown hundreds of balloons carrying rubbish towards the South, including on Tuesday, wile Pyongyang deployed a large group of soldiers to build new fortifications within the heavily armed border between the two Koreas, occasionally drawing warning shots from South Korean counterparts.
4°C