North Korea's launch comes three days after conducting military drills near the South Korean border. Japan has said the projectiles appear to be missiles.
North Korea launched two projectiles into the sea on Thursday afternoon, the South Korean military said, adding they were fired towards open water in the Sea of Japan.
Japan's Defense Ministry said the projectiles appear to be "ballistic-missile-like," adding that they did not enter Japan's airspace.
Thursday's launch comes three days after the North said its troops were conducting artillery drills near its disputed sea boundary with South Korea.
If confirmed to be a missile launch, it would be the latest in a series of weapons tests by North Korea, which defy UN Security Council resolutions banning Pyongyang from firing ballistic missiles. Last month, it fired two "super-large multiple rocket launcher" systems.
North Korea's missile diplomacy
In recent weeks, North Korea has sought to pressure the US to meet a year-end deadline set by the North for proposals to salvage the stalled denuclearization talks.
In June, US President Trump and North Korean leader Kim Jong Un agreed to restart working-level talks, but a brief meeting of the two sides in October in Sweden ended without progress after the North broke off talks.
Japanese Prime Minister Shinzo Abe said Thursday that multiple missile launches by North Korea are a "serious challenge" for Japan and the rest of the world.
"Such acts by North Korea are unhelpful for efforts to ease tension on the Korean peninsula," Jeon Dong-jin, director of operations for South Korea's Joint Chiefs of Staff, told a news briefing.
North Korea demands the lifting of sanctions and the abandonment of joint military drills by the US and South Korea in exchange for scaling back its nuclear weapons program.
wmr/stb (Reuters, dpa, AFP, AP)