North Korea test-fired a ballistic missile into the sea off its east coast on Wednesday, South Korea's military said, ahead of a summit between U.S. and Chinese leaders who are set to discuss Pyongyang's arms programme.
The missile flew about 60 km (40 miles) from its launch site at Sinpo, a port city on the North's east coast, the South Korea's Office of the Joint Chiefs of Staff said in a statement. Sinpo is home to a North Korean submarine base.
The launch comes just a day before the start of a summit between U.S. President Donald Trump and China's President Xi Jinping, where talks about adding pressure on the North to drop its arms development will take centre stage.
"The launch took place possibly in consideration of the U.S. -China summit, while at the same time it was to check its missile capability," a South Korean official told Reuters about the military's initial assessment of the launch.
The missile was fired at a high angle and reached an altitude of 189 km (117 miles), the official added.
Any launch of objects using ballistic missile technology is a violation of U.N. Security Council resolutions. The North has defied the ban, saying it infringes its sovereign rights to self defence and the pursuit of space exploration.
The launch drew swift condemnation from Japan, with Prime Minister Shinzo Abe saying further provocative action was possible.
Japan's Chief Cabinet Secretary Yoshihide Suga described the launch as "extremely problematic" and said Tokyo had lodged a strong protest.
South Korea's foreign ministry also condemned the launch as a blunt challenge to a series of U.N. Security Council resolutions targeting North Korea's nuclear and missile programme. Seoul called a National Security Council meeting and vowed to respond strongly in case of further provocations.
"The United States has spoken enough about North Korea. We have no further comment," U.S. Secretary of State Rex Tillerson said in a terse statement.
North Korea failed in an attempt to launch a ballistic missile two weeks ago from its east coast. Earlier in March, it fired four missiles towards Japan, some of which came as close as 300 km (190 miles) to its coast.
The reclusive state has also conducted two nuclear weapons tests since January 2016.
The U.S. and South Korean militaries said initial assessments indicated the launch was of a KN-15 medium-range ballistic missile, which would be the same kind North Korea test-launched in February.
Pyongyang tested a new type of medium- to long-range ballistic missile in February, which it later said was an upgraded, extended-range version of its submarine-launched ballistic missile (SLBM).
North Korea has carried out several SLBM tests near Sinpo.
"While it is entirely possible it was the land-based KN-15, it very well could have been a test of their SLBM system that was conducted on land," said Dave Schmerler, an expert at the California-based James Martin Center for Nonproliferation Studies.
The North is believed to be developing an intercontinental ballistic missile (ICBM) that can hit the United States and its leader, Kim Jong Un, has vowed to test-launch one at any time.
Experts and officials in the South and the United States believe Pyongyang is still some time away from mastering all the technology needed for an operational ICBM system, such as re-entry of the atmosphere and subsequent missile guidance.
Trump wants China to do more to exert its economic influence over unpredictable Pyongyang to restrain its nuclear and missile programmes.
Ahead of the U.S.-China summit in Florida, Trump had threatened to use crucial trade ties with China to pressure Beijing into more action on North Korea.
A senior U.S. White House official said Trump wanted to work with China and described the discussions over North Korea as a test for the U.S.-Chinese relationship.