The Ulchi Freedom Shield exercises will continue in South Korea through September 1 and will include field exercises using planes, vessels, tanks, and perhaps tens of thousands of soldiers. However, North Korea views the exercises as invasion preparations.

The United States and South Korea have begun their largest joint military exercise in years in response to the escalating nuclear threat posed by North Korea.

The exercises could enrage Pyongyang, which has accelerated its weapons testing to a record pace this year while regularly threatening war with Seoul and Washington amidst a protracted diplomatic impasse.

The Ulchi Freedom Shield exercises will continue in South Korea through September 1 and will include field exercises using planes, vessels, tanks, and perhaps tens of thousands of soldiers.

However, North Korea views the exercises as invasion preparations.

Cho Joong-hoon, a spokesman for South Korea’s Unification Ministry, which oversees inter-Korean issues, stated that the South has not noticed any unusual activities or indications from the North.

In recent years, the United States and South Korea suspended some of their regular drills and limited others to computer simulations to make room for diplomacy with North Korea due to COVID-19 concerns.

North Korea conducted the drills after rejecting South Korean President Yoon Suk Yeol’s offer to trade denuclearization measures for economic gains last week.

Kim Yo Jong, the increasingly influential sister of North Korean leader Kim Jong Un, characterized Mr. Yoon’s proposal as dumb and emphasized that the North had no intention of trading away the weaponry her brother views as his only chance for survival.

She sharply criticized Mr. Yoon for conducting military exercises with the United States and for Seoul’s refusal to prevent anti-Pyongyang propaganda pamphlets and other “dirty garbage” from being blown across the border by South Korean activists.

She also derided US-South Korean capabilities for monitoring the North’s missile activity, claiming that Seoul misidentified the launch location of the North’s most recent missile tests on Wednesday, hours before Mr. Yoon encouraged Pyongyang to return to talks at a news conference.

Ms. Kim earlier this month threatened South Korea with “deadly” reprisal for the recent COVID-19 outbreak in North Korea, which Pyongyang claims was caused by leaflets and other materials released by southern activists.

Concerns exist that the threat portends a provocation, such as a nuclear or missile test or even border conflicts, and that the North may attempt to escalate tensions around the time of the joint exercises.