WASHINGTON — The Federal Reserve has raised its key interest rate for the fourth time this year to reflect the U.S. economy’s continued strength but signaled that it expects to slow its rate hikes next year.

Wednesday’s quarter-point increase, to a range of 2.25 percent to 2.5 percent, lifted the Fed’s benchmark rate to its highest point since 2008. It will mean higher borrowing costs.

The Fed’s move came despite President Donald Trump’s attacks in recent weeks on its rate hikes and on Chairman Jerome Powell personally.

The central bank has raised rates with steady regularity as the U.S. economy has strengthened. Wednesday’s was the Fed’s ninth hike since it began gradually tightening credit three years ago.

But a mix of factors — a global slowdown, a U.S.-China trade war, still-mild inflation, stomach-churning drops in stock prices — has led the Fed to consider slowing its rate hikes in 2019 to avoid weakening the economy too much.

It’s now likely to suit its rate policy to the latest economic data.

For now, most U.S. economic barometers are still showing strength. The unemployment rate is 3.7 percent, a 49-year low. The economy is thought to have grown close to 3 percent this year, its best performance in more than a decade.