The top diplomats of South Korea, Japan and China on Sunday reaffirmed the need to hold a trilateral summit at the "earliest" possible time, Seoul's foreign minister said following their first three-way meeting in more than four years.

Foreign minister Wang Yi met his South Korean counterpart Park Jin, and Japanese foreign minister Yoko Kamikawa in the southern port city of Busan.

"The three ministers reaffirmed ... to hold the summit, the pinnacle of the trilateral cooperation system, at the earliest, mutually convenient time," South Korean Foreign Minister Park Jin told reporters following the talks.

"We agreed to expedite the necessary preparations," he added, without giving a specific time frame for the summit.

No leaders' summit has been held since 2019.

At a meeting with his Chinese counterpart, South Korea's Park asked Beijing to play a "constructive role" in denuclearising the North, terming Pyongyang's latest satellite launch a serious threat to his country's national security.

Wang said China "has always played and will play a constructive role" in easing the situation in the region, a statement from Beijing's foreign ministry read. (AFP)