The White House labelled North Korea's claims the United State has declared war on North Korea as "absurd".
North Korea's foreign minister accused US President Donald Trump of declaring war against his country and said Pyongyang was ready to defend itself by shooting down US bombers.
"We have not declared war on North Korea and frankly the suggestion of that is absurd," White House press secretary Sarah Huckabee Sanders said on Monday in response to the rogue state's claims.
The latest threats stoked a week-long war of words that began when the American leader threatened in his address to the United Nations General Assembly to "totally destroy" North Korea if it launches an attack.
Ms Sanders also took issue with the suggestion Pyongyang would have the right to shoot down US planes near North Korean airspace.
"It's never appropriate for a country to shoot down another country's aircraft when it's over international waters," she said.
Alarm over Pyongyang's nuclear and ballistic missile programs dominated this year's gathering of world leaders at the UN, amid fears the heated rhetoric could accidentally trigger a war.
