US consumer inflation was hotter than anticipated in September, government data showed on Wednesday, as Washington's war with Tehran pushed energy costs higher, deepening strains on American households ahead of next month's midterm elections. The uptick underscores voter worries over high costs of living, and comes as US President Donald Trump is campaigning in US states to shore up support for his Republican party as it tries to retain control of Congress. The consumer price index (CPI) was up more than analysts expected in September, rising 3.7 percent on a year-on-year basis, said the US Department of Labour. This was a notable acceleration from the 3.4 percent reading in August. Economists had forecast a slightly cooler reading of 3.6 percent, according to MarketWatch. On a monthly basis, costs jumped 0.6 percent from August to September, the biggest gain in five months, up from a 0.4 percent increase the previous month. Petrol costs accounted for more than half of the jump, surging 9.1 percent on a monthly basis, Wednesday's report said. Excluding the volatile food and energy sectors, "core" CPI was up 2.6 percent from a year ago. Surging investment in data centres and AI has also pushed up prices for computer chips and the consumer electronics that use them. Higher inflation will likely put more pressure on the US Federal Reserve to lift its key interest rate at its next meeting later this month. Economists noted that the report showed price increases were spread more broadly across the economy than in recent months. “The report was worse than expected,” Bill Adams, chief US economist at Fifth Third Bank, said in a note to clients. “Price increases were widespread. ... Consumer demand seems to be holding up better than the downbeat consumer surveys would suggest, helping businesses maintain pricing power." Wednesday's figures are the last major inflation data to be released before the upcoming elections. Ongoing inflation has taken a toll on Trump’s standing with US voters. A poll by The Associated Press-NORC Center for Public Affairs Research found that just 17 percent of US adults approve of his handling of the cost of living issue. And only 26 percent approve of his handling of the economy overall, a new low. Higher prices are eroding Americans' earnings. The US Labor Department also said on Wednesday that average weekly paycheques, when adjusted for inflation, shrank last month compared with a year ago for the first time since May. (Agencies) Edited by Cecil Wong