The missiles were launched from the southwestern coastal town of Jangyon and flew across North Korea before landing in the sea off the country's east coast, according to a statement from South Korea's Joint Chiefs of Staff

North Korea fired two short-range ballistic missiles Tuesday in another show of force after the United States and South Korea began military drills that Pyongyang sees as a rehearsal for an invasion, according to Seoul.

The missiles were launched from the southwestern coastal town of Jangyon and flew across North Korea before landing in the sea off the country's east coast, according to a statement from South Korea's Joint Chiefs of Staff. It also stated that the South Korean military had increased its surveillance posture and readiness in close coordination with the US.

According to Japanese Prime Minister Fumio Kishida, officials are still gathering details about the North Korean launches, and there have been no immediate reports of damage in Japanese waters.

Pyongyang may conduct additional weapons tests in the coming days in retaliation for the allies' military drills, which are scheduled to last until March 23. North Korean leader Kim Jong Un ordered his troops to be ready to repel what he called his country's rivals' “frantic war preparations move” last week.

Concerns about North Korea's nuclear programme have grown significantly since the North tested a barrage of missiles, many of which were nuclear-capable, and openly threatened to use them in potential conflicts with the United States and South Korea last year.

North Korea appears to be using the long-stalled talks with the US and the expanding US-South Korean drills to bolster its weapons arsenals in order to gain leverage in future dealings with the US.

North Korean threats, combined with China's growing assertiveness, have prompted the US to seek to strengthen its alliances with South Korea and Japan. However, some experts believe that a stronger Washington-Seoul-Tokyo partnership may prompt Pyongyang, Beijing, and Moscow to strengthen their own trilateral ties. China and Russia, both embroiled in separate conflicts with the US, have repeatedly thwarted US and ally efforts to tighten UN sanctions on North Korea.