Japan's defence minister issued a direct public warning Tuesday that security cooperation among Japan, the United States and South Korea is essential to regional stability, after President Donald Trump ordered a reduction in joint military exercises with Seoul and described his personal relationship with North Korean leader Kim Jong Un in warm terms.
Defence Minister Shinjiro Koizumi made the remarks in Sydney during a visit to Australia. "As Japan faces the most severe and complicated security environment in the post-war era, the cooperation among Japan, the United States and South Korea is critical to the peace and stability of the region," Koizumi told journalists.
Trump announced Sunday that he had directed the Pentagon to scale back what he called "inappropriate and hostile" military drills with South Korea. The exercises in question are the 11-day Ulchi Freedom Shield drills, designed to prepare U.S. and South Korean forces for a potential conflict with North Korea. Pyongyang has long condemned the exercises as rehearsals for an invasion.
On Monday, Trump insisted his approach was making the situation "much safer," pointing to his ties with Kim. Trump met Kim three times during his first term but has not met him since returning to the White House in January 2025. Asked in the Oval Office whether Kim had responded to his messages, Trump said: "Yeah, he has." When pressed on the state of those conversations, Trump said "it's very positive" but provided no further detail.
Trump also offered an extensive personal defense of the relationship. "Kim Jong Un has always treated me with great respect," Trump said. "I understand him. He understands me."
The White House's outreach to Pyongyang came alongside a rebuke of Seoul. Trump criticized South Korea for failing to support Washington's military campaign against Iran—a war the president has described as aimed at preventing Tehran from acquiring a nuclear weapon. The criticism added a second layer of strain to the U.S.-South Korea alliance at the same moment Washington was reducing joint military activity.
South Korean officials sought to contain the diplomatic damage. Seoul's presidential office said Tuesday that the Ulchi Freedom Shield exercises do not reflect "any intention to attack North Korea or escalate tensions on the Korean peninsula," and that officials had begun the drills as scheduled. South Korean officials also expressed hope that Trump's personal rapport with Kim would eventually draw Pyongyang back to negotiations.
Seoul's unification ministry, which oversees relations with the North, said it could not confirm whether direct communications between Kim and Trump were taking place.
Australia's Deputy Prime Minister and Defence Minister Richard Marles, who hosted Koizumi in Sydney, added Canberra's voice to the concerns. Marles said Australia was "very concerned about North Korea's nuclear programme as well as its missile programme" and that his government had "consistently made that point."
The coordinated statements from Tokyo and Canberra reflect the unease that Trump's moves have generated across U.S. treaty allies in the Indo-Pacific. Japan hosts roughly 54,000 U.S. troops and has watched North Korea accelerate missile tests in recent years. The Ulchi Freedom Shield drills are a cornerstone of the deterrence posture that Tokyo relies on to manage the security threat from Pyongyang.
North Korea has not publicly responded to Trump's comments. Kim's government has historically refused to engage in diplomacy while U.S.-South Korea military exercises are underway, framing the drills as proof that Washington cannot be trusted as a negotiating partner. Whether a reduction in the scale of those exercises opens the door to fresh talks remains unstated by any party.
