North Korea claims to have successfully tested an intercontinental ballistic missile (ICBM) that can strike targets anywhere in the world, following its most recent launch.
The missile, which the US and South Korea had said was an intermediate-range projectile, landed inside Japan's exclusive economic zone on Tuesday.
The South's president, Moon Jae-in, said his country's military was analysing the launch and the possibility the missile was an ICBM.
One analyst suggested the projectile could have enough range to strike the US state of Alaska.
The Kim Jong-un regime had trailed a "major announcement" earlier today.
US Pacific Command confirmed it had tracked "the "single launch of a land-based, intermediate range ballistic missile" for 37 minutes after it lifted off from an airfield north-west of Pyongyang.
The North has previously conducted satellite launches that critics say were disguised tests of its long-range missile technology, and it has conducted four launches since Mr Moon took office in May.
The infographic below, created by statistics agency Statista for The Independent, shows the escalating pace of the Kim regime's missile testing.
Mr Moon has pledged to seek dialogue with the Kim regime to curb its nuclear ambitions, a strategy on which he and US President Donald Trump reportedly agreed during their recent meeting.
Mr Trump responded to the launch by asking, "Does this guy have anything better to do with his life?"
UK Foreign Secretary Boris Johnson said: "This is yet another reminder of the grave danger that North Korea poses to her neighbours, particularly Japan and South Korea, who are our friends and allies.
"Regardless of the variety of missile launched, any test of this kind breaks UN Security Council resolutions once again.
"I expect this will be on the agenda at the upcoming G20 summit and addressed at the UN over the coming days.
"The international community must redouble its efforts to impose a price on this regime, which strains every nerve and sinew to build nuclear weapons and launch illegal missiles, even as the people of North Korea endure starvation and poverty."
David Wright, co-director of the Global Security Program at the US-based Union of Concerned Scientists, said the assessments of the flight time and distance suggest the missile might have been launched on a "very highly lofted" trajectory of more than 2,800km.
The same missile could reach a maximum range of roughly 6,700 km on a standard trajectory, Wright said in a blog post.
"That range would not be enough to reach the lower 48 states or the large islands of Hawaii, but would allow it to reach all of Alaska," he said.
Japanese chief cabinet secretary Yoshihide Suga suggested the altitude of this missile might have been higher than earlier tests. He did not give further details, including the distance of the flight and where in Japan's exclusive economic zone in the Sea of Japan the missile landed.
Additional reporting by agencies
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