A hard-hitting report on the nuclear-armed totalitarian state also strongly criticized its denial of basic freedoms of thought, expression and religion, and its abduction of citizens of neighbouring South Korea and Japan.
"Systemic, widespread and gross human rights violations have been and are being committed by the Democratic People's Republic of Korea, its institutions and officials," said the report by the Commission of Inquiry on North Korea set up in March 2013 by the UN Human Rights Council.
"In many instances, the violations of human rights found by the commission constitute crimes against humanity," the report said.
"These are not mere excesses of the State; they are essential components of a political system that has moved far from the ideals on which it claims to be founded," it said.
"The gravity, scale and nature of these violations revealed a State that does not have any parallel in the contemporary world."
North Korea refused to cooperate with the probe, which has claimed the evidence it has used is "fabricated" by "forces hostile" to the country.
Commission chair Michael Kirby wrote to North Korean leader Kim Jong-un — the third ruler of the communist dynasty founded by his grandfather in 1948 — to give him a last chance to put his country's side.
In a January 20th letter, reproduced in the report, Kirby told Kim he could face justice personally for the crimes committed by the system he runs.
"Any official of the Democratic People's Republic of Korea who commits, orders, solicits or aids and abets crimes against humanity incurs criminal responsibility by international law and must be held accountable under that law," Kirby wrote.
The report said options included the UN Security Council referring the country to the International Criminal Court or setting up an ad hoc tribunal.
The United States welcomed the report, saying it "clearly and unequivocally documents the brutal reality" of North Korea's abuses.
But Pyongyang's key ally China strongly opposed such a move, saying it would "not help resolve the human rights situation" and that "constructive dialogue" was the answer.
North Korea has long faced international sanctions over its atomic weapons programme, but activists said that justice for its rights record was long overdue.
"This has been six decades of human rights abuse in its most extreme and callous form," said Juliette de Rivero of Human Rights Watch.
Denied access to North Korea, the commission gathered evidence at hearings in South Korea and Japan with North Korean exiles — dubbed "human scum" by the regime.
Most potential witnesses were afraid to testify even on a confidential basis because of fears of reprisals against relatives still in the country.
North Korea's crimes against humanity entail "extermination, murder, enslavement, torture, imprisonment, rape, forced abortions and other sexual violence, persecution on political, religious, racial and gender grounds, the forcible transfer of populations, the enforced disappearance of persons and the inhumane act of knowingly causing prolonged starvation," the report said.