Maine Senator Susan Collins and six other senators have urged President Donald Trump’s administration to reverse its plan to bring Russian diesel to U.S. and global markets.

The senators, four Republicans and three Democrats, said Sunday that the proposal conflicts with a 2022 ban on Russian energy imports intended to prevent U.S. money from supporting Russia’s war against Ukraine. Trump said Russia would supply more than 300,000 tons of diesel immediately, another 500,000 tons in November and further shipments afterward. He said the added supply would lower prices.

A White House official said Friday that the Treasury Department had issued a license allowing Russian diesel to reach global markets. The Treasury’s Office of Foreign Assets Control said the authorization was issued at the president’s direction.

The dispute comes amid high fuel prices in Maine. AAA put the state’s average diesel price at $6.45 a gallon Monday morning, compared with $3.87 a year earlier and a current national average of $6.27.