The national average price for a gallon of regular unleaded gasoline in the United States is the lowest it's been in more than four years, motor club AAA said.

AAA reported a national average price Wednesday of $3.43, relatively unchanged from last week, but 7 cents lower than one month ago and 16 cents less than this date in 2013. The price also reflects the lowest price in four years, the motor club said.

AAA said the price at the pump reflects a steady decline in crude oil prices, which make up nearly 60 percent of the retail price for gasoline.

"While geopolitical developments in Ukraine and Iraq remain front page news, oil markets have marched steadily lower reflecting the assessment that global supplies remain unaffected," AAA said in a report published Tuesday.

Gasoline prices in the United States typically fall after the Labor Day holiday as the high demand during the summer tapers off and refineries start to shift to a winter blend of gasoline, which is less expensive to produce.

The U.S. Energy Department said it expects the monthly average price per gallon to keep falling through the end of the year to reach $3.30 by December.