Tokyo secretly asked Beijing not to make territorial claims to the Japan-controlled Senkaku Islands in the East China Sea to avoid friction ahead of the Japanese emperor's visit to China in 1992, according to Japanese diplomatic documents declassified Wednesday.

Then-Japanese Ambassador to China Hiroshi Hashimoto asked influential Chinese officials to refrain from publicly speaking about the issue of the uninhabited islets and historical disputes, in line with a secret order from then-Prime Minister Kiichi Miyazawa in April 1992, the Foreign Ministry's records showed.

The visit, which had been repeatedly requested by Beijing, was made by former Emperor Akihito in October that year, marking the 20th anniversary of the normalization of diplomatic ties in 1972.