"If they don't help us with North Korea, then I can do what I've always said I want to do," he told The New York Times on Thursday.
All year, Trump has repeatedly warned Beijing of punitive tariffs that will come if China continues with what Washington deems unfair trade practices. "They have to help us much more," he told the Times.
The president has taken an aggressive stance toward China over the last 24 hours. Separately on Thursday, Trump tweeted that there will "never be a friendly solution to the North Korea problem" if Beijing continues to aid Pyongyang.
Speaking to the Times at what was apparently an impromptu interview at the Trump International Golf Club in Florida, the president also said he expects fair treatment from an ongoing inquiry about Russian interference in the 2016 election.
"I think he's going to be fair," Trump said, referring to special counsel Robert Mueller, who is leading the probe, while repeatedly insisting that his associates did not collude with Moscow. Trump's comments come as other Republicans attempt to discredit the ongoing investigation.
The probe "makes the country look very bad, and it puts the country in a very bad position," the president said. "So the sooner it's worked out, the better it is for the country."
"Another reason that we're going to win another four years is because newspapers, television, all forms of media will tank if I'm not there because without me, their ratings are going down the tubes," he said.
Read his full interview with the Times.