"The ones that will suffer the most are ordinary people", said Foreign Ministry spokesman Geng Shuang in a statement.
KCNA said on Tuesday the exercises were "simulating an all-out war", including drills to "strike the state leadership and nuclear and ballistic rocket bases, air fields, naval bases and other major objects".
The unnamed Foreign Ministry spokesman said: 'The large-scale nuclear war exercises conducted by the United States in succession are creating touch-and-go situation on the Korean peninsula and series of violent war remarks coming from the USA high-level politicians amid such circumstances have made an outbreak of war on the Korean peninsula an established fact.
North Korea said that further escalation through joint drills "will only invite more awful retaliation and precipitate their self-destruction".
North Korea's Foreign Ministry has once again criticized the latest drills in the peninsula, saying that frequent drills and U.S. threats of preemptive war are making the idea of a new war on the peninsula unavoidable and "an established fact".
North Korea has long spoken out against joint drills between the US and South Korea.
North Korea launched its new Hwasong-15 missile a week ago, claiming to have achieved its goal of becoming a nuclear state.
One B-1B strategic bomber was deployed on the Korean peninsula to carry out the U.S Pacific Command's "Continuous Bomber Presence (CBP) mission", U.S. Air Force confirmed to NK News, adding that the drill was not part of Vigilant Ace 18.
Russia also has communication channels open with North Korea and is ready to exert its influence on the country, the RIA news agency quoted Russian Deputy Foreign Minister Igor Morgulov as saying on Tuesday. Their exercise was simulated to target key North Korean facilities including nuclear and missile sites.
B-1 flights represent the US's go-to response for North Korean provocations like missile tests, and the bomber flights always draw a strong, sometimes dangerously escalating response from Pyongyang.
USA national security adviser H.R. McMaster said at the weekend the possibility of war was "increasing every day". The Pentagon said it has "no intent" to move out any dependants.
The rising tensions coincide with a rare visit to North Korea by United Nations political affairs chief Jeffrey Feltman, the highest-level UN official to visit North Korea since 2012.