President Donald Trump has said the US will “substantially reduce” joint military exercises with South Korea, citing his “very good relationship” with North Korea’s leader Kim Jong Un.

He also noted on Truth Social that South Korea had recently declined to join the US in the “denuclearisation” of Iran.

“These exercises are not only costly, with much of these costs paid for by the United States of America (as usual!), but send a signal that is totally inappropriate and hostile,” Trump posted.

Neither Seoul nor Pyongyang has commented. The decision comes after North Korea this month conducted ballistic missile tests that are banned by the United Nations.

Trump said in his social media post on Sunday that it was “too late to cancel”, as the US and South Korea were due to start their annual military exercises on Monday.

He added: “While somewhat unrelated (?), I recently asked the President of South Korea if they would like to join us in the Denuclearization of the Islamic Republic of Iran, and they said, ‘No thanks!'”

Last week, US and South Korean military leaders held a joint press conference announcing Ulchi Freedom Shield.

They said the 11-day event would be similar in scale to previous years, with about 18,000 South Korean soldiers participating.

During the news conference, military leaders also mentioned North Korea’s deployment of troops to aid Russia’s war against Ukraine.

US military spokesperson Ryan Donald said “our training accounts for that threat”, referring to North Korean soldiers returning from the battlefield. About 28,500 American military personnel are stationed in South Korea.

On Friday, North Korea’s foreign ministry condemned the joint military drills as “a rehearsal for an aggressive war”.

The joint exercises come days after South Korea, the US and Japan detected the second North Korean missile test in days.

Pyongyang has accelerated efforts to expand its nuclear and missile programmes since the collapse in 2019 of Kim’s high-profile diplomacy with Trump during his first term in the White House.

He became the first ever sitting US president to set foot in North Korea when he visited seven years ago.

Trump’s pointed remark about South Korea in his social media post seemed to hint at possible frustration with Seoul for declining to make direct military or logistical contributions to the US hostilities with Iran.

He has also expressed displeasure with other allies for their hesitance to get involved in the conflict, including Japan, France and the UK.

Trump’s move to downsize joint military exercises with South Korea is not without precedent.

He suspended the exercises entirely in 2018, during denuclearisation negotiations with Kim.

The exercises were again scaled back in 2020 during the Covid-19 pandemic.

Last week, South Korea’s president proposed talks with its northern neighbour on officially ending the war between the two that is technically still active since an armistice was signed in 1953.