North Korea on Tuesday denounced Japanese Prime Minister Shinzo Abe as an "Asian Hitler" intent on amassing military power under the guise of ensuring regional stability.
The attack in an editorial carried by the North's official KCNA news agency followed commentary by the ruling party's newspaper Rodong Sinmun last month that described Abe as a "militarist maniac" for trying to amend Tokyo's pacifist constitution.
Abe said last month that Japan's pacifist post-World War II constitution, which limits its military to self-defence, could be amended by 2020.
The KCNA editorial, entitled "Is this the emergence of an Asian Hitler?" said the Japanese premier was fuelling fears of North Korea's missile and nuclear threats in order to justify his country's military expansion.
"Ultra-rightwing groups led by Abe … are trying to shift the focus of international criticisms from Japan to somewhere else," it added.
"There is no difference between the fascist maniac Hitler, who waged battle against communists to justify another war, and the reckless Abe who is using confrontation with North Korea to justify Japan's new militarist ambitions," it added.
North Korea repeatedly harangues Japan over its failure to atone for its 1910-45 occupation of the Korean peninsula and for its claims to Korean island territory.
It also took exception to Abe's December visit to the Yasukuni war shrine that honours Japan's war dead including several high-level officials executed for war crimes after World War II.
The visit was widely condemned by regional neighbours South Korea and China as a slap in the face of victims of Japan's wartime aggression.
"The latest reckless behaviour that has stirred the region is reminiscent of Hitler, who worked so hard to encourage war in post-World War I Germany," KCNA said, calling on Abe to "wake up" from his "militarist fever."
The North's nuclear and missile programmes are of long-standing security concern to Japan, which is a member of the stalled six-party talks on Pyongyang's nuclear ambitions.