YEONCHEON, South Korea/TOKYO - North Korea fired more than 10 ballistic missiles into the sea on Saturday, South Korea's military said, as the U.S. and South Korean forces conducted military drills and U.S. President Donald Trump renewed overtures towards Pyongyang for dialogue.

Japan's coast guard said it had detected what could be a ballistic missile that fell into the sea. It appeared to have fallen outside Japan's exclusive economic zone, public broadcaster NHK said, citing the military.

The missiles were launched from an area near the capital Pyongyang, around 1:20 p.m. (0430 GMT) towards the sea off the country's east coast, South Korea's Joint Chiefs of Staff said in a statement.

North Korea has test-launched a wide range of ballistic and cruise missiles for more than two decades in a push to develop the means to deliver nuclear weapons, which it is believed to have successfully built.

As a result, Pyongyang has been under multiple U.N. Security Council sanctions since 2006 but it remains defiant, despite severe obstacles they created to its trade, economy and defense.

South Korea and Washington this week launched the annual major drills in South Korea, which they say are purely defensive, aimed at testing readiness against military threats from North Korea.

Hundreds of U.S. and South Korean troops conducted river-crossing drills on Saturday with hardware including tanks and armoured combat vehicles, overseen by the commander of their combined forces. The U.S. military has about 28,500 troops and squadrons of fighter jets stationed in South Korea.

North Korea frequently displays its anger at such exercises, saying they are "dress rehearsals" for armed aggression against it by the allies.

On Thursday, South Korea's Prime Minister Kim Min-seok met U.S. President Donald Trump in Washington to discuss ways to reopen dialogue with the North. Trump is eager for any opportunity to sit down with North Korean leader Kim Jong Un, South Korea's Kim told reporters.

-Reporting by Jack Kim, Sebin Choi, Heejin Kim in Seoul, Daewoung Kim in Yeoncheon, South Korea, Anton Bridge in Tokyo; Editing by William Mallard/Reuters