The average price of a gallon (3.79 liters) of diesel in the United States was $6.50 on Friday, up from $5.61 a month earlier, according to the American Automobile Association (AAA), which tracks fuel prices daily.

President Donald Trump said on Tuesday at the United Nations General Assembly in New York that he had urged aides to consider keeping more diesel at home: “I’ve said let’s not send out the diesel. We make a lot of diesel,” he said. Energy analysts and industry groups warn that an export ban could have unintended consequences and push fuel prices up in the United States and abroad.