A high-ranking North Korean official says the United States and South Korea will face even greater security threats for going ahead with annual joint military drills set to proceed this week.

In a statement, Kim Yo Jong, who is also the sister of North Korean ruler, Kim Jong Un, said the war games are an "unwelcome, self-destructive action".

She said the drills threaten the people of North Korea and raise tensions on the Korean Peninsula. 

"The United States and South Korea will face a more serious security threat by ignoring our repeated warnings to push ahead with the dangerous war exercises" she warned.

Kim said U.S. military actions showed that Washington's talk of diplomacy is a hypocritical cover for aggression on the Peninsula saying peace would only be possible if Washington withdrew it’s forces from the South. 

She also says Pyongyang would boost its "deterrent of absolute capacity", including for a "powerful preemptive strike" to counter the ever-increasing U.S. military threat.

North Korea had warned its Southern neighbor against going ahead with the exercises, saying it will hurt efforts made by the two sides to rebuild relations.  

Pyongyang views the military drills as a rehearsal for an invasion of its territory. 

Despite leaving it late to make a decision, Seoul decided to move forward with the maneuvers.

Kim Yo Jong accused the South of "treacherous treatment" for going ahead with the drills shortly after a hotline between Pyongyang and Seoul was reconnected in a bid to ease tensions.

She said the exercises were an "act of self-destruction for which a dear price should be paid as they threaten the safety of our people and further imperil the situation on the Korean peninsula".

Kim added "they are the most vivid expression of the U.S. hostile policy towards (North Korea), designed to stifle our state by force" accusing Seoul of "perfidious behaviour" 

The U.S. Department of Defense has declined to comment on the North Korean statement saying it was against policy to comment on “training.”

A spokesperson said "combined training events are a ROK-U.S. bilateral decision, and any decisions will be a mutual agreement" using the initials of South Korea's official name.

South Korea's Defense Ministry also declined to comment on the drills. A spokesman told a briefing that Seoul and Washington are still discussing the timing, scale and method of the annual exercises.

However, military sources have told media that South Korea and the U.S. began preliminary training on Tuesday with larger, computer-simulated exercises scheduled for next week.

The United States has around 28,500 troops stationed in South Korea following the 1950-1953 Korean War. A conflict that did not end with a peace deal, leaving the peninsula in a technical state of war.

North Korea's reaction may come as a setback to efforts by the North and the South at reopening a joint liaison office and hold a summit later as part of attempts to reestablish ties. 

The drills have sparked rising tensions on the Peninsula after a thaw in relations.

In recent years, the exercises have been scaled back to facilitate talks aimed at dismantling Pyongyang's nuclear and missile programs in return for U.S. sanctions relief.

But the negotiations collapsed in 2019 after the administration of former President Donald Trump demanded too much while refusing to lift any sanctions.