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South Korea will burn like a "sea of fire." Seoul's "rat-like" president will be struck with a "bolt of lightning." The country's media companies will be blown up in missile strikes.

North Korea has fired off many memorable threats at Seoul and Washington over the years. This week brought the promise of a pre-emptive nuclear strike on the United States because of U.N. sanctions punishing the North's Feb. 12 nuclear test.

Seoul has not burned, and experts think Pyongyang lacks the technology to build a warhead small enough to mount on a long-range missile, or to accurately fire such a missile at the United States. A conventional war, however, is considered a real possibility. In 2010, attacks blamed on Pyongyang killed 50 South Koreans.

Here's a timeline of some of North Korea's more vivid threats in its 65 years of existence:

— January 1951: Six months after invading North Korean forces started the Korean War, North Korean leader and founder Kim Il Sung says in a speech that U.S. and South Korean forces were the actual invaders and had prompted his army to retaliate. Kim vows to annihilate the North's enemies.

— January 1952: Kim Il Sung likens U.S. forces to Nazis and says that the war is turning into a mass grave for U.S. forces.

— May 1972: Kim Il Sung tells Harrison Salisbury and John Lee of The New York Times that because of perceived U.S. hostility, "we are always making preparations for war. We do not conceal this matter."

— March 1993: North Korea declares a "semi-state of war" to protest joint U.S.-South Korean war games that it says threaten its security. Amid a standoff with Washington over its nuclear program, it also threatens to withdraw from the Nuclear Non-Proliferation Treaty.

— 1994: In an appearance of what will become a well-worn phrase, a North Korean negotiator threatens to turn Seoul into "a sea of fire." Fearing war, South Koreans clear store shelves of instant noodles, water, gas and other necessities.

— September 1996: North Korea threatens "hundredfold and thousandfold retaliation" against South Korean troops who had captured or killed armed North Korean agents who had used a submarine to sneak into the South.

— January 2002: After President George W. Bush labels North Korea part of an "axis of evil" with Iraq and Iran, Pyongyang calls the remark "little short of a declaration of war." North Korea's Foreign Ministry warns it "will never tolerate the U.S. reckless attempt to stifle the (North) by force of arms but mercilessly wipe out the aggressors."

— January 2010: North Korea's powerful National Defense Commission warns that the country will initiate a "retaliatory holy war" against South Korea over Seoul's alleged contingency plan to deal with potential unrest in the North.

— May 2010: After a Seoul-led international investigation blames a North Korean torpedo for the sinking of a South Korea warship that killed 46 sailors, Pyongyang issues a denial and warns of a "prompt physical strike." In November 2010, the North attacked a front-line island, killing four South Koreans.

— November 2011: A day after South Korea conducts large-scale military drills near the island hit by the North in 2010, the North's Korean People's Army threatens to turn Seoul's presidential palace into a "sea of fire."

— April 2012: North Korea holds a massive rally denouncing conservative South Korean President Lee Myung-bak as a "rat." It says he should be struck with a "retaliatory bolt of lightning" because of his confrontational approach toward Pyongyang.

— June 2012: North Korea's military warns that troops have aimed artillery at seven South Korean media groups to express outrage over criticism in Seoul of ongoing children's festivals in Pyongyang. It threatens a "merciless sacred war."

— October 2012: An unidentified spokesman at the powerful National Defense Commission warns that the U.S. mainland is within range of its missiles and says Washington's recent agreement to let Seoul possess missiles capable of hitting all of North Korea shows the allies are plotting to invade the North.