President Donald Trump's decision to pull the U.S. out of the Iran nuclear deal and re-impose tough sanctions on the Middle Eastern nation is already costing Americans at the gas pump.

With U.S. motorists getting ready to hit the highway for the summer driving season, pump prices have been moving up sharply – topping $3 a gallon in several Western states, where transportation costs typically add to the retail price of motor fuel.

Nationwide, the price of a gallon of regular gasoline hit $2.96 this week, according to the Energy Information Administration. That's up from $2.49 a gallon a year ago, a gain of 19 percent.