South Koreans were taken aback by President Trump when he referred to North Korean leader Kim Jong Un as a “pretty smart cookie.”

The South Korean newspaper Segye Times referred to Trump as a “rugby ball” — a metaphor for someone who takes unpredictable bounces — in a headline about the remarks, The Associated Press reported.

South Korea’s Yonhap news agency attempted to explain in an article what “smart cookie” meant and wrote that the comments could be an effort to justify potential future actions by the U.S. to increase pressure against the North.

North Korea hasn’t directly responded to Trump’s “smart cookie” comments. A commentary in the state-run Minju Joson previously slammed Trump for “bellicose hysteria.”

{mosads}”The Trump administration would be well advised to learn how humbly the preceding administrations were put in the awkward position of lowering the fist of pressure they had raised before” North Korea, the commentary said.