Beijing- Donald Trump has been blasted as a ‘diplomatic rookie’ who must learn not to cross Beijing by Chinese state media, which warned the U.S. could pay dearly for his naivety.

The president-elect was attacked by Chinese newspapers this week, just days after he created potential diplomatic controversy by calling Taiwan and criticizing China’s government.

Trump’s protocol-shattering call with Taiwanese president Tsai Ing-wen and a subsequent Twitter tirade against Beijing’s policies could upend the delicate balance between the world’s two largest economies, the country’s media outlets said.

“Provoking friction and messing up China-U.S. relations won’t help ‘make America great again’” a front-page opinion piece in China’s People’s Daily said.

The nationalist Global Times newspaper’s Chinese edition also ran a page-one story on Trump’s “inability to keep his mouth shut,” damning his “provocation and falsehoods.”

Trump fired off two tweets on Sunday blasting China for devaluing its currency, taxing American imports, and building military installations in the South China Sea.

Official reaction from Beijing has been muted, but China often uses state media to telegraph its policy positions, sometimes employing rhetoric beyond the diplomatic pale.

The Global Times’ English-language edition filled its opinion pages with editorials slamming Trump.

Noting that Sino-U.S. relations had reached a delicate equilibrium thanks to years of careful management, an editorial in the paper warned Trump: “can make a lot of noise but that does not exempt him from the rules of the major power game.”

“He doesn’t have sufficient resources to deal with China wantonly, the second largest economy, the biggest trading country and a nuclear power,” the paper continued.

“Trump’s reckless remarks against a major power show his lack of experience in diplomacy. He may have overestimated the power of the U.S..”

“He is trying to pillage other countries for U.S. prosperity,” it warned, but instead he will unwittingly “smashing the current world economic order” of which the U.S. is the “biggest beneficiary.”

“This call was no accident,” Trey McArver, analyst for China Politics Weekly, said.

“It is clear that Trump associates, including chief of staff Reince Priebus, have had repeated contact with Tsai and her people in recent months and were well aware of what they were doing.”