Wang, the most senior Chinese official to have commented publicly on the issue, said Japan was crossing a red line that must not be touched, according to an official statement posted on the Chinese Ministry of Foreign Affairs' website on Sunday.
He accused Japanese Prime Minister Sanae Takaichi of attempting to intervene militarily over Taiwan.
Wang was referring to comments on November 7 in which Takaichi told a questioner in parliament a hypothetical Chinese attack on democratically governed Taiwan could trigger a military response from Tokyo.
The ensuing row, the biggest China-Japan crisis in years, has spread to trade and cultural relations.
On Friday, China raised the issue with United Nations Secretary-General Antonio Guterres, vowing to defend itself.
Beijing views democratically governed Taiwan as its territory and has not ruled out the use of force to take control of the island.
Taiwan's government rejects Beijing's claims and says only the island's people can decide their future.
Japan's Foreign Ministry did not immediately respond on Sunday to a request for comment on Wang's remarks.
In response to the letter to the UN, the ministry on Saturday dismissed China's claims as "entirely unacceptable" and said Japan's commitment to peace was unchanged.
Taiwan's Foreign Ministry on Sunday condemned the letter to the UN.
"The letter not only contains rude and unreasonable content but also maliciously distorts historical facts," the ministry said in a statement.
"Furthermore, it violates Article 2(4) of the UN Charter, which prohibits the threat or use of force in international relations."
Wang said that in responding to Japan's move, "China must resolutely hit back - not only to safeguard its sovereignty and territorial integrity, but also to defend the hard-won postwar achievements secured with blood and sacrifice".
If Japan "persists in its wrong course and continues down this path", all countries and people have the right to "re-examine Japan's historical crimes" and "resolutely prevent the resurgence of Japanese militarism", he said.
China is Japan's largest export market after the US, buying about $US125 billion ($A194 billion) of Japanese goods in 2024 - mainly industrial equipment, semiconductors and automobiles, according to UN COMTRADE data.
