US Defense Secretary Jim Mattis stressed diplomacy as the way to deal with the North Korean crisis on Friday during talks with his South Korean counterpart in Hawaii, a day after Seoul's top diplomat said a military solution would be unacceptable."Diplomacy should impose reason on Kim's reckless rhetoric and dangerous provocations," Mattis said, referring to North Korean leader Kim Jong Un. He added that military options were meant to ensure diplomats spoke from a position of strength.