A key measure of US consumer inflation in April took its biggest jump in five months as prices for fuel, shelter and medical care rose, government data showed today. 

But other signs of price pressures fell short of expectations, extending the recent trend of low inflation despite rising wages and falling unemployment. 

US President Donald Trump quickly hailed the new inflation reading, saying it left the US economy in pole position.

"Really good, very low inflation!" he said on Twitter. "We have a great chance to 'really rock!'" 

The latest figures came as Trump more than doubled import duties on a vast tranche of Chinese imports.

Economists say could begin to pinch American retail consumers who have so far felt little from the US-China trade war. 

The Labor Department's Consumer Price Index - which tracks costs for household goods and services - rose by a weaker than expected 0.3% compared to March, with most of the increase due to rising fuel prices. 

With the volatile food and fuel categories stripped out, the "core" index rose only 0.1% for the third month in a row. Costs for used cars and trucks, clothing and household furnishings all fell. 

But compared to April of last year, gains appeared stronger. Over the last 12 months, the index rose 2%, the third consecutive monthly gain and the largest increase since November.  

Meanwhile, the core index rose by an even faster 2.1%, returning to February's levels. 

In-home medical care for the elderly rose by the fastest pace in nearly a decade at 3.5%. 

Prices for audio equipment rose by 4.1%, the largest 12-month gain since 1981.

The US Federal Reserve now forecasts no further rate increases in 2019 amid signs of a potential slowdown in economic growth, but some economists say price pressures are due to return later this year as the jobless rate continues to tumble.