The costs of petrol, food and other necessities jumped in May, raising inflation in the United States to a new four-decade high and giving American households no respite from rising costs.

Consumer prices surged 8.6 percent last month from 12 months earlier, faster than April’s year-over-year surge of 8.3 percent, the US Department of Labor said.

On a month-to-month basis, prices jumped 1 percent from April to May, a steep rise from the 0.3 percent increase from March to April. Much higher petrol prices were to blame for most of that increase.

Rampant inflation in the US has imposed severe pressures on families, forcing them to pay much more for food, petrol and rent and reducing their ability to afford discretionary items, from haircuts to electronics. Lower-income and Black and Hispanic Americans, in particular, are struggling because, on average, a larger proportion of their income is consumed by necessities.

US President Joe Biden was scheduled to address price rises on Friday while speaking at the Port of Los Angeles, the busiest in the US. For more than a year, dozens of ships have lined up outside, as COVID limited the capacity to unload ships, disrupting supply chains.

Economists do expect inflation to ease this year, though not by very much. Some analysts have forecast that the inflation gauge the government reported Friday — the consumer price index — may drop below 7 percent by year’s end. In March, the year-over-year CPI reached 8.5 percent, the highest such rate since 1982.