Japan said in December it had spotted a new buoy in its exclusive economic zone (EEZ) south of Yonaguni Island, near Taiwan, and demanded that China remove it immediately.

The Japan Coast Guard issued a statement late Wednesday saying that the buoy was no longer in place.

A spokesman told AFP on Thursday that this means all Chinese buoys in Japanese economic waters have been removed.

Japanese media said this could signal an intention by Beijing to improve strained ties with Tokyo, as China faces political and economic pressure from US President Donald Trump's government.

"I decline to speculate on China's intentions," top government spokesman Yoshimasa Hayashi told reporters on Thursday when asked about the removal of the buoy.

Beijing had in July 2023 installed another buoy within Tokyo's EEZ -- near a group of islets that Japan controls and calls the Senkakus, but are also claimed by China which calls them the Diaoyus.

In February, China moved that buoy out of Japan's EEZ, the coast guard spokesman said.

Tokyo accused Beijing earlier this week of conducting unnotified maritime scientific research within its EEZ, near the remote atoll of Okinotori in the Pacific Ocean.

Adding to decades-old strain between the two countries over history and territorial disputes, Chinese-Japanese ties have soured recently due partly to Beijing's ban on seafood imports from Japan following Tokyo's 2023 release of treated wastewater from the Fukushima nuclear plant.

Increased Chinese military activities, including brief intrusions into Japanese territory, have also led to a deterioration in Japanese public sentiment towards China.

This has been fuelled by the 2024 fatal stabbing of a Japanese schoolboy in China, and a series of detentions of Japanese nationals by the Chinese authorities.