Italy said some U.S. customs authorities have requested tariffs above the rate agreed with the European Union on imports such as Grana Padano and Parmigiano Reggiano cheeses, and that it was seeking guarantees the lower figure will be applied. The US and EU last week locked in a framework trade deal reached in July that includes a 15% U.S. tax on most imports from the 27-nation EU.

"Italy has always supported a frank and constructive dialogue with the United States and will continue to do so by insisting on the proper application of the agreement," Foreign Minister Antonio Tajani said in a statement on Wednesday. "We will protect our businesses, our workers, and our manufacturing excellence by every means at our disposal."