Seoul: North Korea fired at least one ballistic missile which flew about 800km (500 miles) before hitting the sea off its east coast, South Korea's military said on Friday, as the isolated state stepped up its defiance of tough new UN and US sanctions.
A US official told Reuters in Washington it appeared to be a medium-range missile fired from a road-mobile launcher. That would mark North Korea's first test of a medium-range missile, capable of reaching Japan, since 2014.
The missile, launched from north of the capital, Pyongyang, flew across the peninsula and into the sea off the east coast early Friday morning, South Korea's Office of the Joint Chiefs of Staff said in a statement.
It appeared the North may have fired a second missile soon after from the same region, with a projectile disappearing from radar at an altitude of about 17km, the statement said.
South Korea did not confirm the type of the missiles. But 800km was likely beyond the range of most short-range missiles in North Korea's arsenal.
The North's Rodong missile has an estimated maximum range of 1,300 km, according to the South's defence ministry.
Friday's launch quickly provoked a barrage of criticism and appeals.
Chinese Foreign Ministry spokesman Lu Kang urged North Korea to abide by UN resolutions and not do anything to exacerbate tensions.
The US State Department in a statement urged North Korea to focus on taking concrete steps toward fulfilling its international commitments and obligations.
Japan lodged a protest with North Korea through its embassy in Beijing, Prime Minister Shinzo Abe told parliament.
"Japan strongly demands North Korea to exercise self-restraint and will take all necessary measures, such as warning and surveillance activity, to be able to respond to any situations," Abe said.
South Korea's Unification Ministry said Pyongyang should focus on improving the lives of its people and that provocative actions would help nothing.
North Korea often fires missiles during periods of tension on the Korean peninsula or when it comes under pressure to curb its defiance and abandon its weapons programmes.
Last week, the North fired two short-range missiles into the sea off its east coast and its leader Kim Jong Un ordered more nuclear weapons tests and missile tests.
That came after North Korean media said the North had miniaturised nuclear warheads to fit on ballistic missiles and quoted Kim as calling upon the military to prepare for a "pre-emptive nuclear strike" against the United States and South Korea.
US President Barack Obama imposed new sanctions on North Korea on Wednesday over its nuclear test and satellite launch. The sanctions freeze North Korean government assets in the United States, bans US exports to, or investment in, North Korea, and expands a US blacklist to anyone - including non-Americans - who deal with North Korea.
North Korea conducted its fourth nuclear test on January 6 and launched a long-range rocket on February 7 in defiance of existing UN Security Council resolutions.
The North has reacted angrily to annual joint military drills by US and South Korean troops that began on March 7, calling the exercises "nuclear war moves" and threatening to wipe out its enemies.
The US and South Korea remain technically at war with the North because the 1950-53 Korean War ended in an armed truce instead of a peace agreement. Over the last several weeks, the two Koreas have suspended economic ties over the mounting tensions.
South Korea and US officials this month began discussions on deploying the advanced anti-missile Terminal High Altitude Area Defence (THAAD) system to the US military in the South, despite Chinese and Russian objections.
On Wednesday, North Korea's supreme court sentenced a visiting American student to 15 years of hard labour for crimes against the state, a punishment Washington condemned as politically motivated.