US wholesale inflation rose sharply in April as higher fuel costs linked to the Iran conflict increased pressure on businesses and signalled further price rises for consumers.

New figures released by Bureau of Labor Statistics showed the Producer Price Index climbed 6 percent annually in April, up from 4 percent in March.

On a monthly basis, wholesale prices increased by 1.4 percent, double the pace economists had expected.

The latest figures mark one of the sharpest increases in producer inflation in nearly four years.

According to the report, a 15.6 percent rise in petrol prices accounted for around 40 percent of the overall increase in costs paid by businesses last month.

Economists say rising wholesale inflation could eventually feed through to consumers as companies pass on higher operating expenses through increased prices for goods and services.

The surge comes as the ongoing war involving Iran continues to disrupt global energy markets and drive oil prices higher.

Analysts have warned that sustained increases in fuel and transportation costs could further strain American households already dealing with elevated inflation and affordability pressures across the economy.