Japan criticized their weapon test as violation against UN sanctions resulting in Shinzo Abe's criticism.
North Korea slammed Japanese Prime Minister Shinzo Abe as an "idiot and villain" on Thursday and warned he will never set foot in Pyongyang after he condemned the North's latest weapons test.
Pyongyang last week tested what it called "super-large multiple rocket launchers" but Japan said they were likely ballistic missiles that violated UN sanctions, sparking a colourful personal diatribe against Abe.
"Abe, prime minister of Japan, is an idiot and villain," said Song Il Ho, ambassador of the North's foreign ministry, in a statement carried by the official KCNA news agency.
The Japanese prime minister was "a deformed child" and "an underwit", Song said, accusing Abe of being unable to tell the difference between multiple rocket launchers and missiles.
Japan, which is one of the most hawkish of the major powers on the nuclear-armed North, has relentlessly pursued a summit with its leader Kim Jong Un over the fate of a handful of Japanese abductees in North Korea.
But the statement said: "Abe would be well-advised not to dream forever of crossing the threshold of Pyongyang."
North Korea, whose state media excoriates Japan on a near-daily basis for its wartime aggression, has shown little interest in engagement with Tokyo. Kim has met with US President Donald Trump, China's Xi Jinping, Russia's Vladimir Putin and South Korea's Moon Jae-in in recent years.
The North has a long history of colorful personal attacks against foreign leaders.
It has called Trump a "mentally deranged US dotard" and his predecessors Barack Obama and George W. Bush a "monkey" and "half-baked man".
Pyongyang has also railed against former South Korean president Park Geun-hye as a "witch" and a "crafty prostitute" who had Obama as her "pimp".
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