Senior diplomats from South Korea, Japan and the United States on Friday agreed to bolster their security cooperation and deterrence against North Korea, condemning its repeated ballistic missile launches amid growing concerns over a possible nuclear test by Pyongyang.

During a meeting in Seoul, Sung Kim, U.S. special representative for North Korean affairs, and his South Korean and Japanese counterparts, Kim Gunn and Takehiro Funakoshi, also confirmed their shared view that the North's reinforcement of nuclear and missile development is "a clear and serious challenge to the international community," the Japanese Foreign Ministry said in a statement.

The senior officials underscored that North Korea conducted the latest ballistic missile test on May 25 just after Japan-U.S. and U.S.-South Korea summits, and a meeting of the Quad leaders involving Japan, the United States, Australia and India, according to the ministry.

North Korea has conducted 15 rounds of ballistic missile tests since the start of the year in violation of U.N. Security Council resolutions.

Kim of the United States said that Washington is "preparing" with Tokyo and Seoul to deal with contingencies on the Korean Peninsula. The United States assesses that North Korea is readying its Punggye-ri test site for what could be the seventh nuclear test, he added, highlighting the importance of trilateral cooperation.

The meeting was the first such in-person trilateral talks of the top diplomats in charge of North Korean issues since Yoon Suk Yeol assumed office as South Korea's president last month.

The diplomats also emphasized that it is essential for South Korea, the United States and Japan to cooperate in responding to North Korea's nuclear and missile threats, according to the South Korean Foreign Ministry.

South Korea, Japan and the United States remain on alert for further provocations. If North Korea conducts another nuclear test, it would be its first since 2017.

Kim, South Korea's special representative for Korean Peninsula peace and security affairs, said at the outset of their meeting, open to the media, that their talks are "extremely timely, considering the gravity of the current situation on the Korean Peninsula."

He urged the North to return to the path of dialogue and diplomacy, saying that "North Korea's relentless pursuit of nuclear weapons will only end up strengthening our deterrence."

Amid possible further provocation by Pyongyang including a nuclear test, Funakoshi, director general of the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau, said he believes trilateral cooperation will be "further advanced" under the new South Korean administration, and reiterated that Japan remains open to "serious and sustained dialogue" with North Korea.

Kim of the United States said that ultimately, the goal for the complete denuclearization of the peninsula remains unchanged.

They also discussed offering humanitarian aid to North Koreans who are currently facing hardships caused by the outbreak of the COVID-19 pandemic.

Friday's meeting also came at a time when Japan and South Korea are working to improve bilateral ties, which sank to their lowest level in decades under Yoon's predecessor Moon Jae In.

Seoul and Tokyo have been at odds over a number of issues stemming from Japan's 1910-1945 colonial rule of the Korean Peninsula such as the wartime labor of Koreans and Koreans forced to work as "comfort women" in Japan's wartime military brothels.

There have been recent signs of improvement, with Yoon calling for a future-oriented approach in bilateral relations.