The Federal Reserve’s preferred measure of inflation picked up last month, the latest sign that President Trump’s tariffs are starting to bleed through into consumer prices.

Consumer prices rose 0.3 percent in June and were up 2.6 percent from a year earlier, according to the Personal Consumption Expenditures price index, which the Commerce Department released on Thursday. “Core” prices, which exclude volatile food and energy costs to give a more reliable read of the underlying pace of inflation, also rose 0.3 percent from the prior month and were up 2.8 percent from a year ago.

The June inflation figures represented a modest acceleration from May, when overall prices were up 2.4 percent from a year earlier. Consumer spending also picked up, an encouraging sign for the economy, but one that suggests inflation will remain a concern.

The pickup in inflation could widen divisions among Fed officials, and between the central bank and President Trump.

Fed policymakers are weighing two competing risks right now: On the one hand, there are signs that the economy and the labor market are cooling and could cool further, which would ordinarily call for lower interest rates to encourage spending and investment.

On the other hand, inflation remains above the Fed’s long-term target of 2 percent, and most forecasters expect it to rise at least temporarily because of Mr. Trump’s tariffs, most of which go into effect on Friday morning. That would suggest that interest rates should remain relatively high to prevent inflation from spiraling out of control.

The Fed on Wednesday opted to hold interest rates steady for the fifth consecutive meeting, resisting intense pressure from Mr. Trump for an immediate, and drastic, cut. But policymakers splintered over the decision: Two members of the powerful Board of Governors dissented from the decision, saying they believed they should cut rates, though not by nearly as much as Mr. Trump has demanded.

The Fed’s decision on Wednesday was a foregone conclusion. What they do at their next meeting, in September, is not: Jerome H. Powell, the Fed chair, on Wednesday said that he and his colleagues will base their decision on what the economic data, particularly on inflation and the labor market, show between now and then.

The data on Thursday was from June, and probably won’t weigh heavily on the decision policymakers reach in September. But it showed why inflation remains a concern for most officials at the central bank, and for many economists outside of it.