WASHINGTON — U.S. inflation accelerated last month as the cost of groceries, gasoline and rents rose, a disappointment for families and businesses struggling with higher costs and likely underscoring the Federal Reserve’s resolve to delay further interest rate cuts.

The consumer price index increased 3 percent in January from a year ago, Wednesday’s report from the Labor Department showed, up from 2.9 percent the previous month. It has increased from a 3 1/2 year low of 2.4 percent in September.

The new data shows that inflation has remained above the Fed’s 2 percent target for roughly the past six months after it fell steadily for about a year and a half. Elevated prices turned into a political hurdle for former President Joe Biden. President Donald Trump pledged to reduce prices on “Day 1” if elected, but most economists worry that his many proposed tariffs could at least temporarily increase costs.

Bond yields rose, a sign traders expect inflation and interest rates to remain high.

“We’re really not making progress on inflation right now,” Sarah House, senior economist at Wells Fargo. “This just extends the Fed’s hold.”

Inflation often jumps in January as many companies raise their prices at the start of the year, but the government’s seasonal adjustment is supposed to filter out those effects.

Yet House said inflation’s stubbornness wasn’t just a one-month blip. Consumers — particularly wealthier ones — are still spending at a robust pace, giving many companies less reason to hold down prices. And much of the decline in inflation in 2023 and early last year stemmed from supply-chain improvements, but that trend has mostly played out.

Excluding the volatile food and energy categories, core consumer prices rose 3.3 percent in January compared with a year ago, up from 3.2 percent in December. Economists closely watch core prices because they can provide a better read of inflation’s future path.

Inflation also worsened on a monthly basis, with prices jumping 0.5 percent in January from December, the largest increase since August 2023. Core prices climbed 0.4 percent last month, the most since March 2024.

Grocery prices climbed 0.5 percent just in January, pushed higher by a 15.2 percent surge in egg prices, the biggest monthly increase since June of 2015. Egg prices have soared 53 percent compared with a year ago.

An avian flu epidemic has forced egg producers to cull from their flocks about 40 million birds in December and January. Stores have imposed limits on egg purchases and restaurants have placed surcharges on egg dishes.

The cost of car insurance continues to rise and picked up 2 percent just from December to January. Hotel prices rose 1.4 percent last month, while the cost of a gallon of gas moved up 1.8 percent.

Fed Chair Jerome Powell said Wednesday in testimony before the House Financial Services Committee that the Fed “has made great progress” on inflation “but we’re not quite there yet.”

“Today’s inflation print … says the same thing,” he added. As a result, the Fed wants to keep rates “restrictive for now,” he said. At its current level, the Fed’s rate is restricting borrowing and spending by consumers and businesses, Powell has said.

With inflation down from its 9.1 percent peak in June 2022, the Fed cut its rate to about 4.3 percent in its final three meetings last year. It raised its benchmark rate in 2022 and 2023 to a two-decade high of 5.3 percent to combat inflation.

The Fed’s rate typically influences other borrowing costs for everything from mortgages to credit cards.

Early Wednesday, Trump said on social media that interest rates should be lowered, “something which would go hand in hand with upcoming Tariffs!!!” Yet the tick up in consumer prices makes it less likely the Fed will cut rates anytime soon.

One sign of concern for economists is that goods prices, excluding food and energy, rose 0.3 percent in January from the previous month. Prices for cars, furniture, and appliances had been flat or falling after supply-chain kinks stemming from the pandemic were resolved. Yet now those prices have ticked up even before tariffs have been launched.

Trump has imposed 25 percent tariffs on steel and aluminum, which could push the cost of cars, appliances, and industrial machinery higher. He also said this week he would impose “reciprocal tariffs” on countries that have high duties on U.S. goods.