North Korea is threatening to turn its enemies into a "sea of fire" if Washington continues to challenge the communist state. State run media also deny that Pyongyang told U.S. officials it has a nuclear weapons program. The tough talk comes two days after Pyongyang withdrew from a global arms treaty.

In a commentary in a state run newspaper, Pyongyang repeated its assertion that the United States is to blame for the current crisis. It denies U.S. reports that it had admitted having a nuclear weapons program and says Washington fabricated the allegations because of what it describes as a "sinister intent."

The commentary went on to say that it would turn the "citadel of imperialists," as it called South Korea, into a "sea of fire" if the United States continues to challenge Pyongyang.

This is not the first time that North Korea has threatened violence on the peninsula. It used similar language during an earlier crisis in 1994, caused by its development of weapons-grade plutonium. That crisis brought the United States and South Korea to the brink of war with North Korea.

The current international furor over North Korea nuclear development was sparked in October, when Washington said that Pyongyang had admitted having a banned nuclear weapons program.

Washington considers that a violation of an 1994 agreement under which Pyongyang promised to scrap its nuclear ambitions in return for two light water power reactors and regular deliveries of fuel oil.

Last month, Washington and its allies halted the fuel shipments. Pyongyang responded by moving to reactivate a nuclear plant that can produce weapons grade plutonium. On Friday, it announced it was withdrawing from the Nuclear Non-proliferation Treaty. The move has alarmed the international community and there has been intense diplomatic activity to pressure North Korea into reversing its decision.

In Sunday's media commentaries, Pyongyang called on South Koreans to join in resisting what it called U.S. plans to invade the North. The commentaries also said the United States should stop challenging North Korea over its withdrawal to abandon the nuclear arms control treaty.

North and South Korea remain technically at war because they did not sign a peace treaty when fighting in the Korean War ended in 1953.