North Korea has fired a suspected ballistic missile off its east coast, its first known test since June, South Korean military officials have said.
It came after a US aircraft carrier arrived in South Korea to participate in joint drills, and ahead of a planned visit by Vice President Kamala Harris.
South Korean state-run media said its neighbour may be preparing to test a submarine-launched ballistic missile.
The UN prohibits North Korea from ballistic and nuclear weapons tests.
Japan’s coast guard confirmed the launch, warning ships to “be vigilant”. It said the object appeared to have fallen outside its exclusive economic zone.
The nuclear-powered USS Ronald Reagan docked in the southern port city of Busan on Friday, to take part in joint drills off South Korea’s east coast. The exercises are for the “sake of peace and stability on the Korean peninsula”, according to the South Korean navy.
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Ms Harris will visit South Korea in the coming days as part of a trip to the region that will include the funeral of former Japanese Prime Minister Shinzo Abe.
Tensions on the Korean peninsula have spiked in the past year, with Pyongyang firing a number of ballistic missiles.
South Korea’s President, Yoon Suk-yeol, who took office in May, has promised a tougher stance on North Korea and indicated closer ties with the US.