North Korea has said key cities on the east and west coasts of the United States are within reach of intercontinental ballistic missiles.
Los Angeles and New York, along with the entire US mainland, are believed to be within firing distance of the country, according to a report released by the secretive state.
The regime in Pyongyang claims it conducted a successful test of a missile on Saturday.
North Korea's state TV said it served as a "stern warning" for America, insisting the US wouldn't be safe if they chose to attack.
The test drew condemnation from China and a warning from Donald Trump, who claimed the former might have been able to solve the problem of North Korea on Twitter.
The President said in a separate statement the US would take "all necessary steps" to ensure security of the American mainland.