TOKYO - Japan's top government spokesman on Monday expressed strong regret over China's decision to cancel a ceremonial event to mark the 40th anniversary of the normalization of diplomatic ties between the two countries.

Osamu Fujimura, Chief Cabinet Secretary, told a press conference "it is very disappointing", referring to the cancellation of the event slated to be held in Beijing on Thursday.

Fujimura also said the cancellation "should not influence overall Japan-China ties" and that it remains important for the two countries to "deepen strategic relations of mutual benefit" from a broad perspective.

Chinese authorities informed Japan on Sunday that Beijing wants to postpone the ceremony for the time being, with relations between the two neighbors plummeting to their lowest point in years amid a territorial dispute over Diaoyu Islands in the East China Sea.