Top officials from South Korea, the United States and Japan all expressed concern about North Korea’s provocations while confirming that the door to dialogue remains open a day after the North Korean leader strongly criticized the three nations.

The remarks came during a forum hosted by the Center for Strategic and International Studies in Washington on Tuesday that was attended by South Korean Ambassador to the U.S. Cho Hyun-dong, U.S. National Security Council coordinator for Indo-Pacific affairs Kurt Campbell and Japanese Ambassador to the U.S. Koji Tomita.

Cho said that continued provocations in violation of multiple UN Security Council resolutions by North Korea will only strengthen the trilateral security cooperation among South Korea, the U.S. and Japan.

Seoul's ambassador issued the stance in response to a question about a criticism from North Korean leader Kim Jong-un of joint military exercises among South Korea, the U.S. and Japan as he called the leaders of the three nations “gang bosses.”

Campbell said that continued provocations by North Korea are deeply concerning to the region as a whole, but that the three nations are united in their determination to keep the door of diplomacy open.

The senior White House official also evaluated that the recent South Korea-US-Japan Summit at Camp David showed a sense of three equal, powerful, committed, determined nations meeting on equal terms.