In January, inflation exceeded the 2.9% forecasted by economists and reached 3%, the highest level in six months.
The increase follows weeks after the US central bank said there was substantial uncertainty about the future direction of the economy and decided to keep interest rates.
It presents a dilemma to US President Donald Trump, who proclaimed combating inflation a key component of his campaign last year but has proposed measures that analysts warn could drive up prices, like increased import tariffs.
The new research may force Trump to reevaluate those policies, which would increase tariffs on goods entering the nation, according to Ryan Sweet, chief US economist at Oxford Economics.
