Higher fuel and some food prices have kept the pressure on household costs in a partial measure of inflation for August.

Stats NZ figures showed petrol prices rose 2 percent in July and diesel prices were up nearly 9 percent, as global energy prices turned higher amid renewed US-Iran hostilities, and pressure on fuel supplies.

It was the first rise in fuel prices in four months.

Petrol was nearly 18 percent higher than a year ago and diesel was 46 percent more expensive over 12 months.

Fuel prices make up about 4 percent of the broad inflation measure, the consumer price index (CPI).

Food prices rose 0.3 percent for the month, to be 1.9 percent higher than a year ago, the lowest annual rate since December 2024.

Fruit and vegetables were flat for the month, but 1.6 percent cheaper than a year ago.

"This is the largest annual price decrease in the fruit and vegetables group since March 2025," Stats NZ spokesperson Nicola Growden said.

Food bills were lifted by rises in meat, groceries, and restaurant meals.

Food prices make up about 19 percent of the broad inflation measure, the CPI.

Electricity, and rents were flat or marginally cheaper, with marked falls in domestic airfares, and local commercial accommodation as school holidays ended.

International airfares rose 4 percent on July, driven by higher fares to Europe and Asia, with the annual increase of 21.5 percent the highest in more than three years.

"Because we collect some international airfare prices around four months in advance, price changes that occurred earlier in the year for travel in August are now being reflected," Growden said

The items measured make up about half of the CPI, which quickened to a two year high of 4.1 percent in the year ended June.

The Reserve Bank has started raising its benchmark cash rate to counter high inflation and bring it back to the 2 percent target point.