Senior diplomats from Japan, the United States and South Korea pledged Wednesday to take "specific steps" if North Korea conducts a nuclear test, a Japanese Foreign Ministry official said, with fears growing about such a provocation.

The agreement came at a trilateral meeting in Tokyo between Takehiro Funakoshi, director general of the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau, and his U.S. and South Korean counterparts, Sung Kim and Kim Gunn.

(From L) U.S. special representative for North Korea Sung Kim, Takehiro Funakoshi, director general of the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau, and Kim Gunn, South Korea's special representative for Korean Peninsula peace and security affairs, pose for photos as they meet in Tokyo for trilateral talks on Sept. 7, 2022. (Pool photo)(Kyodo)

They also agreed to keep promoting security cooperation among the three nations to beef up their deterrence against North Korea, which has test-launched ballistic missiles in defiance of a spate of U.N. Security Council resolutions, according to the ministry.

North Korea is believed to have completed preparations for its seventh nuclear test and the first one since September 2017, with speculation mounting that the Asian country may carry out it soon.

Sharing "serious concern" that Pyongyang has been accelerating nuclear and missile development, the three agreed on the necessity of "resolute responses" in the event of a nuclear test, the official said. He did not elaborate what kind of measures they could take.

The diplomats also referred to news that Russia, hit by economic sanctions imposed by Western nations over its invasion of Ukraine since late February, has been buying rockets and artillery shells from North Korea, the official told reporters.

"Generally speaking, we shared the view that any import of weapons and related supplies from North Korea violates relevant U.N. resolutions," the official added.

During the almost two-hour gathering, South Korea's Kim talked about President Yoon Suk Yeol's "audacious initiatives," which include economic aid to the North if the country takes practical steps toward denuclearization, the official said.

On the same day, Masami Oka, Japan's senior deputy minister for defense, and Shin Beom Chul, South Korea's vice defense minister, met in Seoul, confirming the importance of boosting their bilateral and trilateral cooperation involving Washington.

The two also agreed to keep communicating with each other "to resolve the pending issues" between the two nations, the Japanese government said, as their relations deteriorated under the former administration of President Moon Jae In, known as anti-Japan politician.

Shin told reporters that the two talked about an alleged lock-on of fire-control radar on a Japanese Self-Defense Forces patrol plane by a South Korean destroyer in December 2018, adding they will continue to discuss the issue.

The radar lock-on incident has frayed bilateral ties along with wartime history and territorial disputes. Seoul denied the radar irradiation and alleged that the Japanese plane deliberately flew at low altitude near the South Korean naval ships on three occasions.

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