Citing the latest round of United Nations sanctions against North Korea, Tillerson said there's "a unified global message like we've never had before" but that "has to be backed by a strong military outcome if North Korea chooses wrongly". But Dunford also called a military solution to the North Korean threat "horrific".
US President Donald Trump has warned of "fire and fury" if North Korea threatens the United States, and said the US military is "locked and loaded".
Hagerty succeeds Caroline Kennedy, an attorney and daughter of the late U.S. President John F Kennedy, who held the position from 2013 until Trump took office in January.
The two sides indicated they would cooperate to strengthen pressure on Pyongyang as the North continues to develop missile technology and nuclear weapons - perhaps the most significant outcome of the meeting. But his chief strategist Steve Bannon said in an interview published Wednesday night that there are no military solutions to the crisis on the Korean Peninsula.
Senior US officials today insisted they are ready to respond to any North Korean attack, after a White House aide dismissed talk of a "military option". Guam is a US island territory and hosts two USA military bases.
North Korea's leader Kim Jong Un threatened to launch missiles into the waters off of Guam last week.
However, after reviewing the plans, Kim seemed to walk back his threat, saying he would wait and observe the "foolish and stupid conduct of the Yankees".
Kono told Ri his country should take concrete action to comprehensively resolve the nuclear and missile development issue as well as the issue of Japanese nationals abducted to North Korea, based on the 2002 Japan-North Korea Pyongyang Declaration.
Earlier in the week, Dunford and his Chinese counterparts signed an agreement created to "improve communication between their militaries and reduce the chances of miscalculations".
US officials have also said Japan's decision to hike tariffs on frozen beef imports from the United States could harm bilateral trade relations.