U.S. Secretary of State Rex Tillerson says there are "clear signs" sanctions on North Korea over its nuclear weapon program are having an effect.
He made the remarks in Beijing where he's accompanying President Trump on his Asia tour.
Tillerson said the sanctions are creating some stress within North Korea's economy and with some of their citizens, potentially even within the military.
Tillerson did not elaborate on that comment.
Meanwhile at a NATO summit on Thursday, U.S. Defense Secretary James Mattis said the U.S. supports solving the North Korean nuclear crisis through diplomatic means.
Mattis said economic sanctions are intended to either isolate the regime or make them come to the negotiating table.