Twelve senators from both parties have urged President Donald Trump to cancel a diesel agreement he announced with Russian President Vladimir Putin. In a letter sent Tuesday, the six Republicans and six Democrats argued that the arrangement would aid Russia's war effort in Ukraine without meaningfully lowering Americans' energy costs.

Trump said last week that Russia would supply more than 300,000 tons of diesel to the U.S. and global market, with another 500,000 tons in November and one million tons soon afterward. He said a further three million tons would follow within a short period, depending on the condition of Russian refineries.

The senators' objection follows legislation passed this summer directing Trump to impose substantial tariffs on leading importers of Russian oil. The measures were intended to target those helping finance Russia's war in Ukraine. Asked about concerns that diesel proceeds could fund weapons, the White House pointed to Trump's comments to reporters Tuesday; he described the fuel as going to the wider world, not specifically to the United States.