Japan has withheld its annual UNESCO dues, saying it wants to make sure the U.N. body properly functions to foster trust among member nations.

Foreign Minister Fumio Kishida, asked by a reporter, confirmed that Japan withheld dues of 4 billion yen ($40 million) for this year. He refused to say if that was to protest UNESCO's listing last year of Chinese Rape of Nanking documents as a memory of the world.

Kishida said the decision is based on "comprehensive" observations. Japan disputes China's historical views on the 1937 massacre and has criticized the UNESCO decision.

Japan provides 9.7 percent of UNESCO budget, the body's second-largest donor after the U.S. at 22 percent. Washington has suspended its dues since 2011 when Palestine began participating in UNESCO.