TOKYO (Kyodo) -- China has rejected Japan's proposal to hold a trilateral summit with South Korea in January following Japanese Prime Minister Sanae Takaichi's remarks about a Taiwan contingency, diplomatic sources said Saturday.

Japan, this year's chair of the framework, was hoping to hold the summit at an early date, but its realization has become increasingly uncertain as there are no prospects to even discuss a specific timetable for the meeting, the sources said.

Earlier this month, Takaichi said a Taiwan emergency involving the use of military force by China could constitute a "survival-threatening situation" for Japan, possibly allowing it to exercise the right of collective self-defense.

After Takaichi's comments in parliament, China, which insists self-ruled democratic Taiwan is its own territory, urged its citizens to refrain from traveling to Japan and halted seafood imports from its neighbor.

Beijing also notified Seoul of the postponement of a Japan-China-South Korea culture ministerial meeting slated for Monday, underscoring that the fallout from Takaichi's remarks has spread beyond bilateral ties, affecting trilateral cooperation.

The foreign ministers of the three countries had agreed at a gathering in Tokyo in March to hold a summit at an early and appropriate time.

Tokyo sounded out Beijing and Seoul behind the scenes about holding the summit in January, as arranging it before the end of the current year would have been difficult given Japan's Diet is holding an extraordinary session through Dec. 17, the sources said.

China has demanded that Takaichi, known as a pro-Taiwan lawmaker who maintains a hawkish stance on national security, retract the comments, sparking concern that Beijing could escalate its response depending on how she reacts.

If the trilateral summit were to materialize, Chinese Premier Li Qiang is expected to visit Japan, creating a potential opportunity to stabilize bilateral relations, and Tokyo, as chair, intends to continue calling for an early meeting.

China, however, heads into its Lunar New Year holidays in mid-February and the annual National People's Congress will take place in March, leaving a very limited window, according to the sources.

In the past, ties between Tokyo and Beijing deteriorated after Tokyo put the Senkaku Islands, a group of uninhabited islets in the East China Sea claimed by China, under state control in 2012, resulting in the interruption of trilateral summit meetings for around three and a half years.

China and Taiwan have been governed separately since they split in 1949 following a civil war. China regards the island as a renegade province to be reunified with the mainland, by force if necessary.