China has accused Japan's Prime Minister of pushing the two countries towards an "extremely dangerous" confrontation after he visited a controversial shrine to the country's war dead.
China and South Korea reacted with fury after Shinzo Abe became the first Japanese prime minister to visit the Yasukuni shrine in seven years.
The Chinese Foreign Ministry described relations between the two sides as "already grim" and added that the visit on Thursday was "absolutely intolerable".
Among the 2.5 million war dead buried at Yasukuni are several "class A" war criminals, the Japanese leaders who were responsible for starting and waging the war in Asia.
China estimates about 21 million Chinese were killed by Japanese aggression and has accused Japan of denying the extent of war crimes.
Abe, a nationalist who has led Japan into an increasingly fraught relationship with its East Asian neighbours, was broadcast live on television as he entered the shrine.
Japanese leaders have refrained from visiting the shrine in recent years as they sought to build better relations with China.
Abe, dressed in a morning suit and silver tie, was accompanied by a motorcade into the shrine, bowing upon arrival before following a Shinto priest into an inner sanctum.
After the visit, Abe immediately defended his decision in a statement to the press: "Some people criticise the visit to Yasukuni as paying homage to war criminals, but the purpose of my visit today, is ... to renew the pledge that Japan must never wage a war again."
However, the Chinese Government was quick to fire off statements, and summoned the Japanese ambassador to Beijing for a "severe reprimand".
"The essence of Japanese leaders' visits to the Yasukuni shrine is to beautify Japan's history of militaristic aggression and colonial rule," said the Chinese Foreign Ministry. It added the visit was "absolutely unacceptable to the Chinese people" and cautioned Japan "must bear the consequences arising from this".
South Korea, where President Park Geun Hye has made clear she refuses to hold any high-level summit with Japan, also condemned Abe's visit, and the US said it was "disappointed that Japan's leadership has taken an action that will exacerbate tensions with Japan's neighbours".
This month, Abe took Japan another step away from its post-war commitment to pacifism, approving a new five-year defence plan that called for the acquisition of drones and amphibious assault vehicles to strengthen the Japanese military as it continues a stand-off with China over a set of disputed islands.
"China is attempting to alter the status quo by force in the skies and seas of the East China Sea and South China Sea and other areas based on assertions that are incompatible with the established international order," stated a document outlining the plan.
The new defence plan means Japanese military spending will rise by 5 per cent over the term, a modest increase compared to the double-digit ramps in Beijing's defence budget. Nevertheless, the plan drew another rebuke from China, which said that Japan "continues to deny its history of World War II aggression, challenge the post-war order, and harm the feelings of the people of those victimised nations."
Political analysts suggested that Abe had calculated that, with his high ratings in the polls, and with relations with China and South Korea already inflamed by territorial disputes, Thursday was a reasonable time to visit the shrine.
"In terms of foreign policy, this might have been the best timing for him to visit," said Narushige Michishita at the National Graduate Institute for Policy Studies in Tokyo. "The relationship with Korea and China is already at the bottom and, in an ironic way, it cannot deteriorate much further."