SEOUL (Reuters) -South Korea and the United States will face even greater security threats for going ahead with annual joint military drills due to begin this week, Kim Yo Jong, a powerful North Korean official and sister of leader Kim Jong Un, said on Tuesday.

South Korea and the United States began preliminary training on Tuesday with larger, computer-simulated exercises scheduled for next week, the Yonhap news agency reported, despite nuclear-armed North Korea’s warning that the exercises would set back progress in improving inter-Korean relations.

The drills are an “unwelcome, self-destructive action” that threaten the North Korean people and raise tensions on the Korean peninsula, Kim Yo Jong said in a statement carried by state news agency KCNA.

“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 said.

She accused South Korea 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.

North Korea’s reaction to the drills threatens to upend efforts by South Korean President Moon Jae-in to reopen a joint liaison office https://www.reuters.com/world/china/exclusive-north-south-korea-talks-over-summit-reopening-liaison-office-sources-2021-07-28/?taid=6100faa3cb40370001903d27&utm_campaign=trueAnthem:+Trending+Content&utm_medium=trueAnthem&utm_source=twitter that Pyongyang blew up last year and to hold a summit as part of efforts to restore relations.

U.S. Department of Defense spokesman Martin Meiners declined to comment on the North Korean statement and said it was against policy to comment on training.

“Combined training events are a ROK-U.S. bilateral decision, and any decisions will be a mutual agreement,” he said, using the initials of South Korea’s official name.

A spokesman for South Korea’s defence ministry declined to comment on the preliminary drills during a briefing on Tuesday, and said the two countries were still discussing the timing, scale and method of the regular exercises.

The United States stations around 28,500 troops in South Korea as a legacy of the 1950-1953 Korean War, which ended in an armistice rather than a peace deal, leaving the peninsula in a technical state of war.

The exercises have been scaled back in recent years to facilitate talks aimed at dismantling Pyongyang’s nuclear and missile programmes in return for U.S. sanctions relief.

But the negotiations collapsed in 2019, and while both North Korea and the United States say they are open to diplomacy, both also say it is up to the other side to take action.

Kim said U.S. military actions showed that Washington’s talk of diplomacy is a hypocritical cover for aggression on the peninsula, and that peace would only be possible if the United States dismantled its military force in the South.

North Korea would boost its “absolute deterrence”, including a “strong pre-emptive strike capability”, to counter the ever-increasing U.S. military threat, she said.

“The reality has proven that only practical deterrence, not words, can guarantee peace and security of the Korean peninsula, and that it is an imperative for us to build up power to strongly contain external threats,” she said.

(Reporting by Hyonhee Shin and Josh Smith; Additional reporting by David Brunnstrom in Washington; Editing by Stephen Coates)