The ministry's special representative for Korean Peninsula Peace and Security Affairs Kim Hong-kyun held a telephone conversation with Sung Kim, U.S. special representative on North Korean policy earlier in the day, the ministry said in a brief note to the media.
The call was arranged one day after North Korea fired off an SLBM in the East Sea, the third sub launched missile the country has launched so far this year. The projectile flew about 500 kilometers before landing in waters near Japan, drawing condemnation from Seoul, Tokyo and Washington as well as the United Nations Secretary-General Ban Ki-moon.
"Both sides shared the seriousness and graveness of North Korea's recent provocations and agreed to cooperate closely in order to induce a reaction at the international organization level including the United Nations Security Council," the ministry said. The envoys also vowed to maintain a solid combined defense posture against North Korea.
"In addition, they agreed to examine additional measures in response to the provocations," according to the ministry.
The allies will cement their collaboration further to keep sending messages of pressure on North Korea at both multilateral and bilateral levels, including at the approaching session of the East Asia Summit, it said.
The two Kims will hold talks in person "as soon as possible" after setting a detailed schedule in the near future, according to the ministry.
Earlier this month, North Korea said it has resumed reprocessing spent nuclear fuel to produce plutonium for nuclear weapons use, spurring criticism from neighboring countries and the international nuclear watchdog, the International Atomic Energy Agency.
The envoys also discussed how to respond to the reprocessing issue, the ministry said.