North Korea said it tested a new hypersonic weapon designed to evade missile defences, as US President Donald Trump and his South Korean counterpart Lee Jae Myung struggle to revive diplomacy with Kim Jong Un. North Korean state media said on Tuesday that the 'new weapon', which was tested on Sunday, was 'of great significance'. Accompanied by photographs showing an upgraded short-range ballistic missile fitted with a hypersonic glide vehicle, the weapon combines speed and manoeuvrability at low altitude, making it harder to intercept than conventional ballistic missiles.

Only China and Russia currently have such technology in use, 'so... it is a pretty big deal for North Korea', said Peter Ward of the Sejong Institute in Seoul. If operational, the system would 'make Korean missile defences less effective in the event that Kim Jong Un fancies taking potshots at South Korean civilian or military targets.'

Kim, who observed the test with his teenage daughter and purported successor Kim Ju Ae, called the weapon an 'irresistible force' that would be an 'incurable headache' for the regime's adversaries, according to state media. The weapons test will come as a blow to Lee, who is in New York for the UN General Assembly, where he is expected to lay out his ambitions for improved relations with Pyongyang.

Pyongyang has rebuffed those overtures, with one South Korean official stating there was no active dialogue between Pyongyang and Washington or Seoul 'at least not through official channels'. The regime was also unmoved when Trump last month scaled back annual military drills with South Korea, which he said were 'hostile' to Pyongyang. Pyongyang is now in a much stronger position than during Trump's first term, according to analysts.