US President Donald Trump has ordered the Pentagon to "substantially reduce" the annual Ulchi Freedom Shield joint military exercises with South Korea, announcing the move on social media hours before the drills were due to begin — and citing his personal relationship with North Korean leader Kim Jong Un as a key reason.

In a post on Truth Social on Sunday, Trump said he was "not happy" with US participation in the exercises, describing them as costly and sending "a signal that is totally inappropriate and hostile" to a country that, in his view, had been "unthreatening and respectful" during his presidency. He acknowledged it was too late to cancel the drills entirely and said he had instructed Defence Secretary Pete Hegseth to scale them back significantly. Trump also referenced South Korea's refusal to support US efforts on Iran, writing that he had asked Seoul's president whether South Korea would join "the denuclearisation of the Islamic Republic of Iran" and been told "No thanks."

The Ulchi Freedom Shield exercise, one of two major annual drills held by the two allies, runs from 17 to 27 August and was set to involve around 18,000 South Korean troops alongside US forces and personnel from 11 United Nations Command member states. South Korea's defence ministry said the exercises would "proceed as previously notified and scheduled," while the Pentagon referred questions to the White House. The move echoes Trump's first term, when he suspended or scaled back joint exercises after his 2018 summit with Kim in Singapore, calling them "provocative, inappropriate and expensive."

The timing has drawn concern from analysts and officials. Military commanders on both sides had specifically designed this year's drills to incorporate lessons from North Korean troops' battlefield experience in Ukraine, where Pyongyang has deployed forces alongside Russian troops and observed the use of drones, GPS disruption and cyber warfare. A senior US officer noted that North Korea had "contemporary battlefield experience" that directly shaped the threats the exercises were meant to counter. Experts cautioned that Trump's characterisation of North Korea as unthreatening was at odds with a regime that has continued to develop nuclear warheads and ballistic missiles capable of reaching North America, and has deepened military ties with Russia under a strategic partnership signed in June 2024.

Analysts are divided on what the order signals. Some see it as an attempt to reopen diplomatic channels with Pyongyang — Trump posted a photo of himself with Kim at the inter-Korean border village of Panmunjom the day before, fuelling speculation about a potential fourth summit. Others are sceptical that Pyongyang will respond positively to a partial reduction. "The North will only view it as meaningful if the joint exercises are cancelled in their entirety rather than scaled back," one North Korea expert said. A Korea-focused think tank director noted that while Trump may be seeking a diplomatic opening, "the haphazard nature of this move is unlikely to make much of an impression in Pyongyang." The order also prompted criticism from US Senator Andy Kim, who argued that decisions about joint exercises "need to be made jointly — and not announced unilaterally by social media."