President Donald Trump said Sunday that he has directed the Defense Department to scale down joint military exercises with South Korea, citing the country’s refusal to join the war in Iran and his “very good” relationship with North Korea’s Kim Jong Un.

Trump said the large, annual military drills sent a “signal that is totally inappropriate and hostile” to North Korea, a country with which the U.S. has no formal diplomatic ties but which Trump says has been “unthreatening and respectful” as long as he has been president.

“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.

Trump also mentioned South Korea’s refusal to join the Iran war.

“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!’” Trump wrote.

It was not immediately clear what a scaled-down version of the training, set to start Monday only hours after Trump’s announcement, would look like.

South Korea’s embassy in Washington and U.S. Forces Korea, a sub-unified command tasked with carrying out the exercises, did not immediately respond to requests for comment.

The command was set to carry out the Ulchi Freedom Shield training Monday, which would include 18,000 South Korean soldiers, the South Korean military told The Associated Press. The exercises are meant to build understanding among several agencies to ensure “their ability to fortify the combined defense posture and enhance Alliance response capabilities against a spectrum of security threats.” North Korea last week called the drills a “war rehearsal” and threatened to retaliate.

Trump’s announcement comes days after North Korea launched a ballistic missile toward the sea, conducting weapons testing in possible protest of the upcoming U.S.-South Korea military drills.

It also comes a day after the U.S. pulled its last aircraft carrier in Asia, as the USS George Washington was sent to replace the USS Abraham Lincoln — which has drawn scrutiny over conditions on board — in the Persian Gulf.