U.S. President Donald Trump said he was scaling back “costly” and “inappropriate” joint military exercises with South Korea that started Monday, prompting speculation about a return to dialogue with North Korean leader Kim Jong Un.

Citing his relationship with Kim, as well as Seoul’s decision not to join U.S.-led actions against Iran, Trump said in a social media post that he was “not happy” with the current situation.

“Based on my very good relationship with Kim Jong Un … I am not happy with the fact that the United States has, long ago, agreed to participate in Joint Military Exercises with South Korea,” he wrote. “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, to a Country that, as long as Donald J. Trump has been President, has been unthreatening and respectful.”