Federal Reserve officials raised concerns during their May policy-setting meeting that progress on inflation is stalled, while "many" questioned whether policy was restrictive enough to tame price pressures within the economy.

Minutes from the U.S. central bank's May meeting released Wednesday showed that officials are prepared to keep rates elevated after a string of disappointing inflation readings in the first three months of the year – and willing to hike again if needed.

"Various participants mentioned a willingness to tighten policy further should risks to inflation materialize in a way that such an action became appropriate," the minutes said.

Officials voted at the May meeting to hold interest rates steady at a range of 5.25% to 5.5%, the highest level since 2001. In their post-meeting statement, policymakers left the door open to rate cuts later this year, but stressed they need "greater confidence" inflation is coming down before easing policy.

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