President Donald Trump said Sunday that he had ordered the Defense Department to significantly scale back annual joint military exercises with South Korea, citing his relationship with North Korean leader Kim Jong Un and Seoul’s refusal to participate in the U.S. war with Iran.

Trump said the large-scale exercises send what he described as an inappropriate and hostile signal to North Korea, which has long condemned U.S.-South Korean military drills as preparations for a possible invasion.

The president said North Korea had been “unthreatening and respectful” during his presidency and pointed to what he described as his “very good” relationship with Kim.

“Based on the fact that it is too late to cancel, I have instructed Secretary of War Pete Hegseth to substantially reduce the Joint Military Exercises,” Trump wrote on social media.

The announcement came just hours before the annual Ulchi Freedom Shield exercises were scheduled to begin.

Trump also linked his decision to South Korea’s refusal to join U.S. military operations against Iran. He said he recently asked South Korea’s president whether the country would participate in efforts related to the denuclearization of Iran but was turned down.

It was not immediately clear how significantly the exercises would be reduced or which elements would be affected.

South Korea’s Defense Ministry said Monday that Ulchi Freedom Shield, scheduled to continue through August 27, was “proceeding as planned.”

The exercises are a major component of the longstanding U.S.-South Korean security alliance and are intended to strengthen the two militaries’ ability to respond jointly to potential threats on the Korean Peninsula.

North Korea has repeatedly criticized the drills and has sometimes responded with missile launches, military exercises and strongly worded warnings.