US President Donald Trump on Sunday instructed the Pentagon to “substantially reduce” 10 days of joint military exercises with ‌South Korea as they were about to get underway, citing the cost of the drills and Seoul’s refusal to take part in actions against Iran.

Hours before exercises were scheduled to begin, Trump said on his Truth Social site that although it was too late to cancel the drills entirely, he was “not happy” that the US had previously agreed to participate and highlighted his “very good relationship” with North Korean leader Kim Jong Un.

“These exercises are not only costly... but send a signal that is totally inappropriate and hostile, to a Country that, as long as Donald J. Trump has been President, has been unthreatening and respectful,” Trump wrote.

The annual Ulchi Freedom Shield joint military exercises are scheduled to run from August 17 to 27, with about 18,000 South Korean military ⁠personnel participating. The drills are expected to include operations to counter drones, disrupt GPS signals and cyberattacks to adapt to North Korea’s evolving capabilities, officials said last week.

South Korea’s Joint Chiefs of Staff told Reuters that the drills started on Monday as scheduled, but declined comment on Trump’s comments. The country’s presidential office and defence and foreign ministries did not immediately respond on a public holiday in Seoul.

A Pentagon spokesperson referred questions on the matter to the White House, which did not immediately respond to a request for more information on next steps for the drills.

Up-and-down relationship

Trump has long sought to end or curtail military exercises with South Korea, going back to his first term, calling them “provocative” and costly. He has also clashed with Seoul over sharing the costs of stationing 28,500 US troops in South Korea and their role in securing the broader region.

Pyongyang routinely denounces the US-South Korean exercises as preparations for an invasion. North Korea last Wednesday fired a ballistic missile from its eastern coast towards the Sea of Japan, the South Korean and Japanese militaries said, six days after a similar North Korean short-range ballistic missile launch on August 6.

Trump may be trying to improve relations with Kim, said Jenny Town, head of the Stimson Center think ‌tank’s 38 ⁠North program.

“This decision may be part of a larger effort to create a diplomatic opportunity with Pyongyang, as Trump has consistently wanted since coming back to office, although the haphazard nature of this move is unlikely to make much of an impression in Pyongyang,” Town said in an email.

The relationship between Trump and Kim has been a roller coaster for years.

Trump once mocked the North Korean leader as “little rocket man” and threatened Pyongyang with “fire and fury,” while Kim boasted that he would “tame the mentally deranged US dotard with fire.”

Yet they also took part in three summits, with Trump declaring, “we fell in love” after exchanging letters with Kim. None of these efforts led to changes in North ⁠Korea’s nuclear weapons or ballistic missile development.

Even as Trump on Sunday spoke warmly of nuclear-armed North Korea, he pointed to South Korea’s stance on the US-Israeli conflict with Iran.

“While somewhat unrelated (?), I recently asked the President of South Korea if they would like to join us in the Denuclearisation of the Islamic Republic of Iran, and they said, ‘No thanks!’“ Trump wrote.

Exercises shift to simulations

It’s unclear how the Ulchi Freedom Shield drills could be cut back, but in ⁠recent years, they have shifted away from live-fire exercises to computer-simulated missile and cyberattacks.

US military officials have said that North Korean troops, who have fought alongside Russia in its invasion of Ukraine, have gained experience from the conflict, including the growing use of unmanned systems, electronic warfare and cyber operations.

Ukraine said last week that North Korean-made missiles were used in a Russian ballistic missile attack on a steel plant in ⁠Zaporizhzhia that killed seven workers and forced a production halt, with Russia’s Zircon hypersonic missiles also used in the attack.

A high-ranking US Northern Command official, Lieutenant General Joseph Jarrard, last week warned that North Korea had successfully tested intercontinental ballistic missiles with “enough boost to deliver a nuclear payload anywhere in North America,” complicating US homeland defence efforts.