WASHINGTON — The U.S. economy grew at a healthy 3.1 percent rate in the first three months of this year, but signs are mounting that growth has slowed sharply in the current quarter amid slower global growth and a confidence-shaking trade battle between the United States and China.

The gain in the gross domestic product, the broadest measure of economic health, was unchanged from an estimate made a month ago, the Commerce Department said. However, the components of growth shifted slightly with stronger business investment and consumer spending slowing more than previously estimated.

Economists believe growth has slowed sharply in the current April-June quarter to around 2 percent. They expect similar meager gains for the rest of the year.