South Korean military officials cast doubts on Friday on the capabilities of what North Korea called a "hypersonic missile" test fired this week, saying it appeared to represent limited progress over Pyongyang's existing ballistic missiles.
On Wednesday, North Korea launched what its state media said was the country's second hypersonic missile, which is usually defined as weapons that reach speeds of at least five times the speed of sound - or about 6,200 kms per hour (3,850 mph) - and can maneuver at relatively low trajectories, making them much harder to detect and intercept.
While the missile's warhead appeared to reach hypersonic speeds, that capability is shared by other ballistic missiles and Wednesday's test did not appear to demonstrate the range and maneuverability claimed in state media reports, a South Korean military official told reporters.
South Korea assessed that it flew for less than the 700 km (435 miles) claimed by North Korea and showed less than the "lateral" manoeuvrability reported, the official added.
Wednesday's warhead featured a more conical shape than the first claimed North Korean hypersonic missile tested in September, which was glider-like.
"This is neither a hypersonic glide vehicle nor a hypersonic cruise missile, this is a missile with a mobile warhead," the official said of the newest missile, which was first unveiled at a Pyongyang defence exhibition in October.
The assessment mirrors that of international analysts who noted that the test appeared to involve a liquid-fuel ballistic missile with a Manoeuvrable Reentry Vehicle (MaRV), a capability previously fielded by other countries including the United States and South Korea.
"One of my complaints about the 'hypersonic' framing is that it wrongly emphasizes speed when what we really are discussing is maneuverability and accuracy," Jeffrey Lewis, a missile researcher at the James Martin Center for Nonproliferation Studies (CNS), said on Twitter. "So, yeah, the new (North Korea) glider is hypersonic. But more importantly, it's a MaRV."
While such missiles don't have the range of North Korea's largest intercontinental ballistic missiles (ICBMs), analysts say maneuverable weapons can be used to evade missile defences.
On Friday the United States and Japan issued a joint statement pledging to increase joint defence, including against hypersonic weapons.