Tokyo's approval of a new defense plan for the next five years, which outlines China as a "potential threat", was strongly opposed by Beijing and criticized by experts who said it may increase instability in Northeast Asia.
Japan's government approved its new National Defense Program Guidelines and the midterm defense program on Tuesday, which marks a significant upgrade of Tokyo's military capabilities, including the introduction of the first aircraft carrier since World War II, the deployment of long-range missiles, and the development of cyber and space warfare capabilities.
The guidelines said the efforts are necessary given "growing defense challenges in the region", namely tensions on the Korean Peninsula and "concerns about China's military footprint".
Beijing on Tuesday expressed strong dissatisfaction and opposition to Tokyo's "false claims and irresponsible remarks" concerning China's "normal defense construction and military activities".
"The contents of the Japanese documents about China are old-fashioned, and they have made false claims and irresponsible remarks about China's normal defense construction and military activities," Foreign Ministry spokeswoman Hua Chunying said.
"What Japan has done is not conducive to the improvement of the Sino-Japanese relationship, nor to the overall peace and stability of the region."
The plan is controversial both in Japan and overseas, with critics arguing it shifts Tokyo further away from its commitment to strictly defensive capabilities under Japan's post-World War II pacifist constitution.
However, Japanese Chief Cabinet Secretary Yoshihide Suga said on Tuesday that "we believe this is within what is allowed under the constitution".
The plan assumes record military spending of 27.47 trillion yen ($244 billion) through March 2024, according to Japan's Kyodo News.
It calls for the defense ministry to upgrade two flat-top Izumoclass destroyers to enable them to launch fighter jets with short takeoff and vertical landing abilities, like the F-35B stealth fighter.
In a move so as not to contradict its "defense-only" policy, the plan said the new Izumos "will not be an offensive aircraft carrier" because the fighters will "only be used on the vessel in emergencies or for training".
Hua urged Tokyo "adhere to its commitment of a 'defense-only' policy and act cautiously in the field of military and security".
Japanese military commentator Maeda Tetsuo said there is no way to justify the plan for upgrading the destroyers to become an "offensive" carrier with fighter jets on board.
Some analysts echoed that having "offensive" weapons is in direct contravention of the pacifist constitution, a key clause of which reads that "land, sea, and air forces, as well as other war potential, will never be maintained".
Song Zhongping, a military commentator, said Tokyo's plan was "obviously targeting China" and would make an already fragile Sino-Japanese relationship even more uneasy. He added that Japanese Prime Minister Shinzo Abe is using the defense plan to bolster his approval ratings.
"Any move to build its first aircraft carrier would not only violate its pacifist constitution - which forbids it from operating such an attack vessel - but would also make China and other countries that were victims of its aggression (in World War II) very uneasy," he said.
Wu Jinan, a Japanese studies expert, said in a period when the denuclearization negotiations on the Korean Peninsula are underway, Tokyo's plan might provoke a backlash and may intensify naval competition in the Northeast Asia.