U.S. President Donald Trump on Wednesday said he would meet North Korean leader Kim Jong Un later this year, and revealed that Pyongyang possesses “57 very powerful nuclear weapons.”

But Kim’s powerful sister appeared to pour cold water on Trump’s push for reengagement.

Kim Yo Jong said in a report carried by state-run media Thursday that she was “not aware” of Trump’s claim a day earlier that he was in communication with the North Korean leader, while also labeling the U.S. president’s order earlier this week to scale down joint military exercises with South Korea as “one unworthy of comment.”