The launch came as Pyongyang marks the anniversary of the death of leader Kim Jong Un’s father and predecessor Kim Jong Il.
South Korea has accused the North of firing a short-range ballistic missile amid tensions in the peninsula.
Sunday’s launch came as North Korea condemned the United States-led military’s shows of force, including the arrival of a submarine in South Korea as tantamount to “a preview of a nuclear war”.
The missile was launched from the Pyongyang area towards the East Sea at around 10:38pm (13:38 GMT) on Sunday and flew about 570km (354 miles) before falling into the ocean, the South Korean Joint Chiefs of Staff (JCS) said, referring to the body of water also known as the Sea of Japan.
The launch followed warnings from officials in Seoul and Tokyo that nuclear-armed North Korea was preparing to test-fire a missile, including one of its longest-range intercontinental ballistic missiles (ICBMs) this month.
Japan’s Ministry of Defence also said North Korea launched “what appears to be a ballistic missile”, with its coastguard adding that it seemed to have already fallen.
JCS said Seoul, Washington and Tokyo have “closely shared information regarding North Korea’s ballistic missile”, which was launched two days after the US and South Korea held their second session of the Nuclear Consultative Group in Washington on Friday, where they discussed nuclear deterrence in the event of conflict with the North.
A spokesperson for the North’s Defence Ministry on Sunday slammed the allies’ plans to expand a key annual joint military drill next year to include a nuclear operation drill and warned of “a preemptive and deadly counteraction”.
“This is an open declaration on nuclear confrontation to make the use of nuclear weapons against the DPRK a fait accompli,” the statement carried by the KCNA news agency said, using the official acronym for North Korea.
“Any attempt to use armed forces against the DPRK will face a preemptive and deadly counteraction.”
All of North Korea’s ballistic missile activities are banned by United Nations Security Council resolutions, though Pyongyang defends them as its sovereign right to self-defence.
The missile launch also came as Pyongyang marks the anniversary of the death of leader Kim Jong Un’s father and predecessor Kim Jong Il, who died on December 17, 2011.
North Korea last year declared itself an “irreversible” nuclear power and has repeatedly said it will never give up its nuclear programme, which the regime views as essential for its survival.
Last month, Pyongyang successfully put a military spy satellite into orbit. It has since claimed its eye in the sky was already providing images of major US and South Korean military sites.
The UN Security Council has adopted many resolutions calling on North Korea to halt its nuclear and ballistic missile programmes since it first conducted a nuclear test in 2006.
Washington and its allies have also expressed concerns about a potential arms alignment between North Korea and Russia.
They worry that Kim is providing badly needed munitions to help Russian President Vladimir Putin wage the war in Ukraine in exchange for Russian technology assistance to upgrade his nuclear-armed military.