North Korea's armed forces are reported to be awaiting a "final order" from the country's supreme leader Kim Jong-un before launching a campaign against South Korea.
Ahead of a ten-day joint computer-simulated drill to be conducted by the US and South Korea on 11 March, the North's most widely circulated mouthpiece Rodong Sinmun said: "Our front-line military groups, the army, the navy and the air force, the anti-aircraft units and the strategic rocket units, who have entered the final all-out war stage, are awaiting the final order to strike."
The mouthpiece said the North's nuclear weapons are also in full readiness.
"Puppet regimes in the US and South Korea will be turned into a sea of fire in the blink of an eye," said the daily, raising tensions further in the Korean peninsula.
South Korea and the US have been conducting a joint field training exercise codenamed Foal Eagle since 1 March, and this is likely to go on until the end of April.
Nearly 10,000 South Korean troops and 3,500 American forces along with fighter planes are involved in the manoeuvres.
South Korea says the exercises are intended to secure its territories, but Pyongyang charges that they are aimed at the North.
The North has also announced that it will conduct a two-day nationwide military exercise in response to the US-South Korea drill.
Local reports suggest that Kim has also been visiting strategically important military installations in the country in the wake of the volatile situation.
A military source in Seoul has told the Yonhap news agency that Pyongyang is likely to fire short-range missiles or resort to other forms of attack during the drill. The source vowed to retaliate with greater force if South Korean sovereignty is violated.