Finance Minister Nicola Willis has pointed the finger at US President Donald Trump for New Zealand's rising inflation, as StatsNZ figures showed annual inflation climbing to 4.1 percent, the highest level in more than two years. RNZ

Inflation is the rate at which prices go up across the economy over a year. Willis described the increase as a "Trump spike in inflation," driven by higher petrol and diesel prices. She told reporters that without the fuel price increases, annual inflation would have sat at 2.9 percent. That would be inside the Reserve Bank's target band of 1 to 3 percent. The Reserve Bank is the government agency that steers the economy by keeping inflation within that range.

The StatsNZ release contained other pressure points beyond the pump. Electricity prices rose 12 percent on an annual basis, and rates were up 9 percent. Willis said the government was introducing rates caps to help with rising costs, though she did not say how or when.

Labour finance spokesperson Barbara Edmonds rejected the blame. She said government costs had increased by 21 percent over the last two years and GP fees had risen by more than 20 percent over the same period. Edmonds said Willis was blaming overseas factors she cannot control instead of taking responsibility for costs at home.

The broader context is that Willis's explanation works as a political story. The Coalition government was elected on a promise to fix the cost of living, so a high inflation number looks bad for them. Pinning it on Trump and global oil prices gives them a way to say: this is not our fault. But it also opens the government up to the same criticism they levelled at the previous government — blaming things outside their control. Willis's strongest point is her 2.9 percent figure, which shows inflation would be within target if you take fuel out of the picture. Whether voters accept that depends on whether they see petrol prices as separate from their other household costs.

The rates cap announcement, while light on detail, shows the government is looking for things it can fix at home. Rates and electricity take up a good chunk of household budgets, and both went up by around 10 percent or more. The cap on rates targets one of those. Electricity prices are harder to tackle, and Willis did not propose a fix for those.

Edmonds's figure on government costs, up 21 percent over two years, is a reminder that the government has not held back all areas of public spending. GP fees rising more than 20 percent is a particular sore point, because the Coalition campaigned on making health costs more manageable. Labour will keep arguing that even modest domestic inflation is shaped by decisions the government makes.

The big question for the Reserve Bank is whether the fuel-driven inflation is temporary. Think of it like a spike in your grocery bill because a frost wiped out crops — if the next harvest is fine, prices settle back down. If petrol and diesel prices ease, the overall inflation rate could fall back toward the target band without the government doing anything. If they stay high, the Reserve Bank may need to raise its key interest rate. That would flow through to mortgage payments, and the government would feel the fallout at the next election.