Beijing on Monday warned Tokyo against any further sovereignty infringement, as Tokyo confirmed its final plan to "nationalize" China's Diaoyu Islands within the month.

Analysts sounded alarm over Japan's accelerating pace of fanning bilateral spats over territorial issues, saying Tokyo's recent messages to Beijing about cooling tensions may be regard as just a "cover" for its true intentions.

Japanese Cabinet Secretary Osamu Fujimura on Monday confirmed that Tokyo is now "in the final stages" of reaching a deal to "buy" part of the Diaoyu Islands from a so-called private owner by the end of September, Kyodo News Agency reported.