A drastic "mutual distrust" against each nation's defense policy is fueling the deadlock in China-Japan relations, a senior expert said.

Zhang Tuosheng, director of the research department at the China Foundation for International and Strategic Studies, said the two neighbors are questioning each other's expanding military strength at a time when the overall relationship is being haunted by historical and territorial issues.

"In regard to China's defense policies, Japanese politicians and leading media have labeled China as a major threat to navigational freedom and the regional situation.