China's new stealth fighter is based on US technology acquired by Chinese spies during the 1999 Kosovo War, according to Croatia's former military chief of staff.
"Whether the reported new weapons are true or not, in the long run, China will own first-class weapons that are capable of competing with the US war machine," said the Global Times, known for its nationalist tone.
Gates arrives in China on Sunday to smooth over tense defence relations between the two countries -- one year after Beijing cut military ties with Washington in protest against US arms sales to rival Taiwan.
"Apparently, the US is not ready to treat China as a major power. They cannot accept the fact that China will sooner or later possess a first-class military," the editorial said.
"They are too used to the old power structure, in which China and other developing countries have long been treated unfairly."