South Korea has expressed concerns over Pyongyang’s suspected new long-range missile that was displayed in a military parade on Saturday as Seoul urged the resumption of intra-Korean talks.

During the military parade celebrating the 75th year of the founding of North Korea’s ruling party in Pyongyang, a variety of weapons systems were shown to a foreign audience for the first time.

Among the displayed weapons, one is what appeared to be an intercontinental ballistic missile (ICBM) that is larger than any of North Korea’s known ICBMs, and the other would likely be an upgraded version of a missile that can be fired from submarines.

Following an emergency National Security Council meeting, council members in South Korea said they would continue to analyse the strategic significance of North Korea’s disclosed weapons systems and review South Korea’s defence capabilities.

While some experts say they could be mock-ups of missiles under development, their disclosure suggests Pyongyang has been continuously pushing to boost its weapons capability amid an impasse in nuclear diplomacy with the United States.

In a separate statement, South Korea’s foreign ministry also urged the North to return to talks to produce progress in its past commitment to achieving denuclearisation and peace on the Korean Peninsula.

Ties between the two sides remain strained amid the deadlocked nuclear diplomacy between Pyongyang and Washington.

During a speech at the military parade, North Korean leader Kim Jong Un warned he would fully mobilise his nuclear force if threatened, but avoided direct criticism of Washington.

The fact that Kim maintains his self-imposed moratorium on nuclear and long-range missile tests indicates he still wants to keep chances for diplomacy with the US alive.

However, some experts say he will eventually carry out a major weapons test after the US presidential election in November to boost his leverage in potential new negotiations with whoever wins the election.