Prime Minister Shinzo Abe compared current tensions between Japan and China to rivalry between Britain and Germany on the eve of World War One, but his top spokesman denied the Japanese leader meant war between Asia's two big powers was possible.
Sino-Japanese ties, long plagued by what Beijing sees as Japan's failure to atone for its occupation of parts of China in the 1930s and 1940s, have worsened recently due to a territorial row, Tokyo's mistrust of Beijing's military buildup and Abe's December visit to a shrine that critics say glorifies Japan's wartime past.
Abe, speaking to international journalists at the World Economic Forum in Davos, said on Wednesday that China and Japan were in a "similar situation" to that of Britain and Germany before World War One.
Although the rivals then had strong trade ties, that did not prevent the outbreak of war in 1914, Abe said, adding that China's steady increase in military spending was a major source of instability in the region, the reports said.
He also repeated Japan's call for a military hotline to avert an accidental conflict.
China and Japan, the world's second- and third-largest economies respectively, have deep business ties and bilateral trade that was worth nearly $334 billion in 2012, according to Japanese figures.
Chief Cabinet Secretary Yoshihide Suga said that Abe had by no means meant that war between the two Asian giants was possible.
"I don't know the specifics of the prime minister's comment," Suga told a regular news conference in Tokyo on Thursday. But he noted that Abe, in a keynote speech at the forum, said dialogue and the rule of law, not armed forces and threats, were needed for peace and prosperity in Asia.
"He clearly stated that endless military expansion in Asia must be curbed. I believe, in these words, he underscored the importance of peace and stability in Asia," Suga said.