Donald Trump has accused China of currency manipulation and criticised its operations in the South China Sea.
In two tweets, the president-elect asked whether China had asked the US "if it was OK to devalue their currency" or "to build a massive military complex in the middle of the South China Sea?"
"I don't think so!" Mr Trump tweeted, in a move that will doubtless deepen the diplomatic row that began when he spoke to the president of Taiwan.
The call was the first between a US president or president-elect and a leader of the Asian island since ties were formally severed in 1979.
China, which sees Taiwan as a breakaway province, lodged a formal complaint with the US over the call.
Mr Trump had already defended the call on Twitter, stressing that President Tsai Ing-wen had called him.
But as the row rumbled on, he returned to social media on Sunday, writing: "Did China ask us if it was OK to devalue their currency (making it hard for our companies to compete), heavily tax our products going into..their country (the U.S. doesn't tax them) or to build a massive military complex in the middle of the South China Sea? I don't think so!"
The US has previously criticised China's reclamation work in the South China Sea and both sides have accused each other of militarising the waters.
Earlier, Mr Trump warned American companies they would face "retribution" for leaving the US and setting up their business operations abroad.
Writing on Twitter, the billionaire said he would impose a 35% tax on any company selling goods back into the US after taking their operation elsewhere.
Mr Trump made keeping jobs in America and creating new employment opportunities one of the cornerstones of his election campaign.