Washington

A KEY measure of US consumer prices unexpectedly accelerated in July in a broad-based advance, signalling inflation may be firming as the Federal Reserve debates whether to lower interest rates further.

The core consumer price index, which excludes food and energy, rose 0.3 per cent from the prior month, and 2.2 per cent from a year earlier, said a Labour Department report on Tuesday. Both gains exceeded the median estimates of economists, while the broader consumer price index (CPI) advanced 0.3 per cent on the month and 1.8 per cent annually.

Faster inflation may strengthen the hand of policy makers, who are reluctant to keep lowering borrowing costs following last month's quarter-point reduction, as employment and consumer spending remain solid.

At the same time, the latest ratcheting-up of US-China trade tensions and a deepening global economic slowdown are weighing on the outlook, with investors pricing in two to three more moves this year.

Following the report, traders trimmed slightly the amount of Fed easing they have priced in for this year, while the 10-year Treasury yield climbed to its high for the day and the US dollar gained.

Policy makers have struggled to lift inflation toward their 2 per cent target, which is based on a separate Commerce Department index that tends to run slightly below the Labour Department's CPI.

President Donald Trump has repeatedly cited low inflation in his attacks on the Fed and calls for deeper interest-rate cuts.

The 2.2 per cent annual gain in the core CPI followed 2.1 per cent in June and marked the fastest increase since January. The index rose an annualised 2.8 per cent over the past three months, the most since early 2018. The two-month gain of 0.6 per cent was the most in more than a decade.

While the Fed officially targets inflation including all items, policy makers look to the core measures for a better sense of the underlying trend because food and energy prices tend to be volatile.

Tariffs on a wide range of consumer products imported from China, set to take effect Sept 1, may boost inflation further. In addition, declining yields on 10-year Treasuries have effectively wiped out any inflation-adjusted return on the security.

Many key measures within the Labour Department's gauge advanced in July. Shelter costs, which make up about a third of total CPI, rose 0.3 per cent for a second month, while medical care was up 0.5 per cent, apparel advanced 0.4 per cent and used cars and trucks rose 0.9 per cent.

Prices for new vehicles fell 0.2 per cent, the first decline since February.

Energy prices rose 1.3 per cent from the prior month as petrol prices increased 2.5 per cent. A national gauge of retail petrol prices was up on average during the month though it has declined since mid-July. Food costs were unchanged for a second month.

A separate Labour Department report on Tuesday showed average hourly earnings, adjusted for price changes, rose 1.3 per cent in July from a year earlier, following 1.5 per cent in June. Higher inflation tends to eat into wage gains.

Economists surveyed by Bloomberg had forecast the core gauge would rise 0.2 per cent from the prior month and 2.1 per cent from a year earlier, with the broader index rising 0.3 per cent on the month and accelerating to 1.7 per cent on a yearly basis. BLOOMBERG