WASHINGTON — President Trump is getting exactly what he wants on the economy, but it may not last.

The Federal Reserve has abruptly stopped its march toward higher interest rates, as Mr. Trump demanded. The tax cuts he signed in late 2017 are in full swing. His attempt to rewrite the global rules of trade are underway, and he proclaims himself happy with the array of new tariffs he has imposed. His recent comments suggest he is unconcerned about slowdowns in China and Europe, which he considers economic rivals.

But while Mr. Trump points with pride to last year’s economic growth and promises even faster growth to come, there are signs that his most dependable talking point is eroding. On Thursday, the Commerce Department issued a downward revision of its estimates for economic growth in the fourth quarter, pushing one measure of the full year’s growth down as well.

Forecasters outside the White House, including officials at the Fed, expect growth to slow even more this year. Economic data suggests that slowdown is already underway in the first quarter. Manufacturing is losing some of its steam from last year’s rapid growth, and job creation is also moderating. Chief executives of some of the nation’s biggest companies see investment, hiring and sales growth all slowing this year. Three-quarters of business economists say they are more worried about growth undershooting their forecasts than overshooting it, and half have revised those forecasts downward for this year.

White House officials see growth staying above 3 percent for the next few years — and potentially for an entire decade, provided Mr. Trump can continue carrying out his economic agenda, including another round of tax cuts, a $1 trillion infrastructure plan and additional deregulation.