North Korea launches ballistic missiles into sea ahead of South Korean leader's visit to China

North Korea launched multiple ballistic missiles toward its eastern waters Sunday, South Korea’s Joint Chiefs of Staff said in a statement.

The statement said several ballistic missile launches were detected from North Korea's capital region early on Sunday, adding that the missiles flew about 900 kilometres and that South Korea and US authorities were analysing details of the launches.

South Korea's Defence Ministry noted the launches violated UN Security Council resolutions that ban any ballistic activities by North Korea. It urged North Korea to cease provocative actions immediately and respond to South Korea's push to restart talks and restore peace on the Korean Peninsula.

The launches came hours before South Korean President Lee Jae Myung departed for China for a summit with President Xi Jinping. During the four-day trip, Lee’s office said he would request China, North Korea's major ally and biggest trading partner, to take “a constructive role” in efforts to promote peace on the Korean Peninsula.

Japanese Defense Minister Shinjiro Koizumi said that at least two missile launches by North Korea had been confirmed. “They are a serious problem, threatening the peace and security of our nation, the region and the world,” Koizumi told reporters.

North Korea ramps up weapons display ahead of political meet

The launches were the latest weapons demonstration by North Korea in recent weeks. Experts say North Korea is aiming to show off or review its achievements in the defence sector ahead of its upcoming ruling party congress, the first of its kind in five years.

Observers are watching the Workers Party congress to see whether North Korea will set a new policy on the US and resume long-stalled talks between the two countries.

North Korean leader Kim Jong-un has also boosted his diplomatic credentials by aligning with Russia over its war in Ukraine and tightening relations with China. Observers say Kim would believe his leverage has sharply increased to wrest concessions from Trump if they sit down for talks again.

North Korea hasn't announced when it will hold the congress, but South Korea's spy service said it will likely occur in January or February.

South Korea and the US have long asked China to exercise its influence on North Korea to persuade it to return to talks or give up its nuclear programme. But there are questions on how big of a leverage China has on its neighbour. China, together with Russia, has also repeatedly blocked the US and others' attempts to toughen economic sanctions on North Korea in recent years.

Later Sunday, South Korea convened an emergency national security council meeting to discuss the North Korean missile launches. The council reported details of the launches and unspecified South Korean steps to Lee, according to the presidential office.