North Korea last fired an ICBM in December last year, in defiance of long-standing and crippling UN sanctions.
ICBMs have the range to reach the North American continent.
Neighbouring Japan said that it monitored Thursday’s launch, adding that the missile reached the highest altitude ever of over 7,000km.
South Korean and US officials met after the launch and agreed to “take strong and varied response measures”, the South’s military said in a statement.
“Our military maintains full readiness as we closely share North Korean ballistic information with US and Japanese authorities,” it added.
The US called the launch a “flagrant violation of multiple UN Security Council resolutions”.
“It only demonstrates that [North Korea] continues to prioritise its unlawful weapons of mass destruction and ballistic missile programmes over the well-being of its people,” the White House’s National Security Council spokesman Sean Savett said in a statement.
Thursday’s launch comes after South Korea and US accused North Korea of sending troops to Russia to support Vladimir Putin’s war in Ukraine.
The Pentagon estimates that around 10,000 North Korean soldiers have been deployed to train in eastern Russia. A “small number” has been sent to Kursk in Russia’s west, with several thousand more on their way, the US said earlier this week.
The alleged presence of North Korean troops in Russia has added to growing concerns over deepening ties between Putin and North Korean leader Kim Jong Un.
Pyongyang and Moscow have neither confirmed nor denied these allegations.
