WASHINGTON — President Trump lacks official power to make the Federal Reserve cut interest rates, but he may have found a way to force its hand: stoking economic uncertainty.

The Fed’s chair, Jerome H. Powell, has signaled that he and his colleagues could cut interest rates at their upcoming meeting as inflation remains stubbornly low and risks, including Mr. Trump’s trade war with China, threaten economic growth. Mr. Powell, speaking in Paris on Tuesday, reiterated that the Fed would act as appropriate to sustain the economic expansion.

Mr. Trump continues to keep the Fed — and the world — on policy tenterhooks, saying on Tuesday at the White House that the United States had “a long way to go” in its ability to punish China with tariffs and suggesting that he could still impose levies on nearly all Chinese goods.

Mr. Trump said China was under no such pressure from its central bank, noting that President Xi Jinping was “his own Fed.”