Mr Xi gave the chilling advice to his troops during an inspection Chaozhou City, Guangdong on Tuesday. He addressed China’s People’s Liberation Army (PLA) Marine Corps, asking them to “focus your minds and energy on preparing to go to war and stay highly vigilant.”
He added that the marines must be a “multifunctional, rapid response, all-weather and region” force.
Mr Xi also stressed the corps’ “important responsibility” to protect Chinese land, maritime and international interests.
He said: “Marines have many different missions, and the demands on you will vary.
“As such, marines should base your training on battle … and raise training standards and combat ability.”
The address follows China’s 75th anniversary of its war against Japan.
During the tribute event, Mr Xi said China would not let any countries “bully” and “impose! its mandate on China.
Chinese state news outlets have expressed support for the leader’s message.
Last week, the editor of Global Times, Hu Xijin, said: “The [chances of the] Chinese mainland being forced into a war has risen sharply in recent times.
“Thus they want to pull the chestnuts out of the fire.
“Considering that there is also the Taiwan question, the risk of the Chinese mainland being forced into a war has risen sharply in recent times.”
He also recently issued a warning to India on Twitter claiming the PLA was “ready to strike a heavy blow to Indian troops”.
He said: “PLA is training attacking tanks in Tibet region. Yes, it targets China-India border situation.
“China hopes the five-point consensus reached between the two foreign ministers can be implemented, but is ready to strike a heavy blow to Indian troops if they refuse to implement it.”
Both countries have sought a diplomatic solution to the border issues, eventually reaching a five-point agreement to put an end to the territorial dispute in Ladakh.
However, last month tensions rose after Beijing was accused of having “kidnapped” five Indian men in the Himalayas.
Mr Hu said at the time: “Based on what I know, five Indian intelligence members disguised themselves as hunters and crossed the LAC into the Shannan prefecture of China’s Tibet to pry intelligence.
“They were detained by the Chinese side and received warning and education. They will soon be released.”