Zhu Chenghu, a major general in the People's Liberation Army(PLA) who said he was expressing his own views and did not anticipate a conflict with Washington, nevertheless said China would have no option but to go nuclear in the event of an attack.
"If the Americans draw their missiles and position-guided ammunition on to the target zone on China's territory, I think we will have to respond with nuclear weapons," he told an official briefing for foreign journalists on Friday.
Zhu said the reason was the inability of China to wage a conventional war against Washington.
"If the Americans are determined to interfere ... we will be determined to respond," he said.
"We Chinese will prepare ourselves for the destruction of all of the cities east of Xian. Of course the Americans will have to be prepared that hundreds ... of cities will be destroyed by the Chinese," he added.
"Of course the Americans will have to be prepared that hundreds ... of cities will be destroyed by the Chinese"
Maj Gen Zhu Chenghu.
The newspaper observed that it was unclear what prompted the remarks, but noted that they were the most specific by a senior Chinese official in nearly a decade.
During a visit to Beijing earlier this month US Secretary of State Condoleezza Rice said there should be no unilateral change in the status quo over the disputed island of Taiwan.
"That means that we don't support unilateral moves toward independence by Taiwan. It also means that we are concerned about the military balance, and we'll say to China that they should do nothing militarily to provoke Taiwan," she added.