While time is running out, there are still no clear prospects of a formal meeting between President Yoon Suk Yeol and Chinese President Xi Jinping.

"We have a day left (before departing from the United States) and discussions (over an arrangement of the Yoon-Xi meeting) are ongoing," a presidential official told reporters on condition of anonymity Thursday.

"We cannot guarantee that the meeting of the two leaders would actually happen due to the leaders' packed schedules."

There were speculations that Yoon might hold talks with Xi during their time in San Francisco, California, for the Asia-Pacific Economic Cooperation leaders' week. Should the meeting take place, it would be the two leaders' first meeting in a year.

Xi is in the US for the first time in six years, and held a summit with US President Joe Biden on Wednesday.

On Thursday, Xi and Japanese Prime Minister Fumio Kishida held face-to-face talks to mend strained ties largely due to China's ban on Japanese seafood after Japan started disposing of treated water from a crippled nuclear power plant in northeastern Japan.

"From China's perspective, they should prioritize Xi's summit with Biden, and afterward, use the remaining time available for them as efficiently as possible," the official said.

"The matter of Korea-China talks is separate from (Xi's) talks with leaders of the US and Japan. We are ahead of the strategic decision to determine whether it would be beneficial for the two leaders to hold talks (in San Francisco) and return home."

Yoon on Wednesday had a three-minute encounter with Xi, just before the APEC formal session began.

When asked whether Yoon brought up the matter of military ties between Russia and North Korea during the encounter, the official said, "Our diplomacy treats the issue separately from China-related issues." Seoul's Foreign Minister Park Jin last week expressed hopes that Xi could play a constructive role in intervening in arms deals between Russia and North Korea.

Seoul is planning to host a trilateral summit of South Korea, China and Japan before the year's end. Separately, Yoon's office announced in September that Seoul is working to invite Xi to Korea.