Japanese Prime Minister Shinzo Abe says the rocky relationship between Japan and China is comparable to that of Germany and Britain before World War One.
Mr. Abe's comments came at the World Economic Forum in Davos. His spokesman later denied that the prime minister thinks war is inevitable between the two Asian powers.
Tokyo and Beijing have long shared a fraught past, but ties have been especially strained because of a worsening territorial dispute and mutual concerns over each other's military intentions.
Most analysts say strong economic ties make an outbreak of hostilities between the two countries unlikely.
But speaking to journalists Wednesday, Prime Minister Abe pointed out close economic relations did not prevent Britain and Germany from going to war in 1914.
He said trust was essential to prevent conflict, suggesting greater military-to-military communication could help. Mr. Abe also criticized China's increase in military spending as a provocation.
In a later keynote speech, he offered a veiled criticism of China's military activities.
"We must, ladies and gentlemen, restrain military expansion in Asia which could otherwise go unchecked. Military budget(s) should be completely transparent and there should be public disclosure in a form that can be verified".
Mr. Abe did not specifically mention China by name, but the comments were in line with Mr. Abe's previous statements condemning China's increasingly assertive military behavior.
Beijing last year set up an Air Defense Identification Zone in the East China Sea, where China and Japan both claim a series of uninhabited but strategic islands.
Japan, along with its ally the United States and South Korea, have rejected the ADIZ as a unilateral provocation, and say it has heightened regional tensions.
The islands, known in Japan as Senkaku and in China as Diaoyu, have been under Japanese control since 1971. But in recent months, a steady stream of Chinese patrol ships has attempted to change the status quo.
Beijing says tensions were only raised after Japan effectively nationalized some of the islands in 2012, buying them from their private Japanese landowner.
China also reacted furiously to Prime Minister Abe's recent visit to a Tokyo shrine that many Chinese view as a symbol of Japan's military adventures in Asia.
Mr. Abe on Wednesday defended his visit to the Yasukuni Shrine, saying it honors millions of dead Japanese soldiers, and not just war criminals.