SEOUL (Kyodo) -- North Korea has launched several short-range ballistic missiles toward the Sea of Japan, the South Korean military said Tuesday.

Last week, North Korea's state-run media reported that the nation had successfully launched a new type of intermediate-range hypersonic missile toward a simulated target at sea.

North Korean leader Kim Jong Un was quoted by the Korean Central News Agency as saying that the test-firing of the new missile was "mainly aimed to steadily put the country's nuclear war deterrent on an advanced basis."

The latest launch comes around a week before U.S. President-elect Donald Trump takes office on Monday. He held summit talks with Kim, including once in Singapore in June 2018, on the denuclearization of the Korean Peninsula.

South Korea, technically still at war with the North since the 1950-1953 Korean War ended in an armistice rather than a peace treaty, has been mired in a political crisis since President Yoon Suk Yeol briefly imposed martial law on Dec. 3, triggering public outrage.