President Moon Jae-in’s special adviser said Friday that South Korea should not be pushed around by the US as the allies seek to build a united front against North Korea, in a veiled criticism of President Donald Trump’s blunt remarks that South Korea can do nothing without his approval.

During a security seminar with a renowned US security expert in Seoul, Moon Chung-in said Trump should have been more careful with his choice of words instead of making “impromptu, instantaneous” remarks that have been widely criticized in Seoul as a diplomatic insult.

Trump said Wednesday that without his approval of sanctions relief against North Korea, South Korea would not be able to do anything about the matter, including the lifting of its own sanctions on North Korea imposed in 2010 after Pyongyang’s suspected torpedo attack on a South Korean Navy corvette.

“(Trump) knows that the US cannot force us” to accept his opposition to the lifting of South Korea’s own sanctions, Moon Chung-in said at a security seminar hosted by the Yonsei Institute for North Korea Studies and East Asia Foundation, during which 38 North Director Joel Wit delivered the main speech.

“He might have been confused between consultation and approval,” Moon added.