North and South Korea conduct ballistic missile tests within hours of one other.

North and South Korea conducted ballistic missile tests hours apart, illustrating a weapons race on the Korean peninsula while nuclear talks with the North remain stuck.

The North launched two ballistic missiles over its east coast, its first such test in six months and a new violation of UN resolutions.

The tests occurred during a meeting between South Korea and China to discuss the North's nuclear program.

Several hours later, the South conducted its first submarine-launched ballistic missile test.

The missile test, known as the SLBM, was pre-planned and not in response to the North's recent launches. South Korea is now the eighth country in the world to have such technology.

President Moon Jae-in, who attended the test, stated that South Korea now has "enough deterrent to respond to North Korea's provocations at any moment," pushing the South to continue expanding its weapons programs in order to "overwhelm North Korea's asymmetric might."

Kim Yo Jong, the sister of North Korean leader Kim Jong Un, slammed the remarks as unreasonable and unfortunate, warning that they could lead to a breakdown in relations, according to state news agency KCNA.

The short-range missiles flew around 800km (500 miles) at a maximum height of 60km in North Korea's test, according to South Korea's Joint Chiefs of Staff (JCS).

They were launched from the country's central inland areas and flew east towards the Sea of Japan, commonly known as the East Sea, according to the JCS. South Korea and the United States were undertaking investigations to ascertain the type of missile used.

Later, Japan's defense minister stated that the missiles had landed within the country's exclusive economic zone.