Mr. Powell has now signaled that the central bank does not plan move policy in either direction unless something fundamentally shifts. Central bankers do not expect to cut interest rates as long as the economy shapes up as expected, and do not intend to raise them unless inflation moves up and stays there.

That is unlikely to sit well with President Trump, who has been pushing the central bank to slash rates further. In a tweet on Tuesday, Mr. Trump said “the Fed should get smart & lower the Rate,” arguing that comparatively high rates in the United States are putting the country at a disadvantage.

The central bank does not answer to the White House, and officials regularly reiterate that they set a policy with an eye toward their twin goals, which are given to them by Congress.

But they are facing a complicated backdrop when it comes to achieving those targets.

Expectations of a global growth turnaround have been climbing, helped along by an initial trade deal between the United States and China that brings some certainty and forestalls additional tariffs between the world’s largest economies. Mr. Trump also signed a revised North American Free Trade Agreement on Wednesday, bringing more than two years of fraught negotiations to a close.

But those positive signs could be dampened by the outbreak of the new coronavirus, which is forcing quarantines in China, shuttering multinational operations in the country and causing nervousness around the world.