Six senators released a statement earlier this week calling for President Donald Trump to "immediately reverse course" on a deal to buy Russian diesel fuel to offset high prices related to Trump’s war with Iran.

On Oct.11, four Republican and two Democratic senators wrote that the administration had failed to consult with Congress or justify its decision to greenlight the deal. Congress passed legislation directing the White House to impose tariffs on the top importers of Russian oil or natural gas, according to PBS News.

Trump said on social media Oct. 9 that during a phone call with Russian President Vladimir Putin, he had agreed to allow Russia to sell 300,000 tons of diesel to the U.S., followed by an additional 500,000 tons in November and 1 million tons “immediately thereafter.” Russia will deliver an additional 3 million tons “within a short period of time,” Trump claimed.

The Republican senators who issued the statement were Susan Collins of Maine, Lisa Murkowski of Alaska, Thom Tillis of North Carolina, and John Curtis of Utah. The Democratic senators were Jeanne Shaheen of New Hampshire and Richard Blumenthal of Connecticut.

In the statement, the senators said that Congress banned Russian energy imports in 2022 to stop the U.S. from helping finance Putin’s war against Ukraine. “Congress was clear: the U.S. should not import oil from Russia until it ends its aggression against Ukraine and ceases threats against our NATO Allies,” the statement reads.

Speaking to reporters outside the White House on Oct. 12, Trump said the Republican senators who signed onto the statement “can’t really be serious” and claimed that importing more Russian diesel would help U.S. farmers.

Energy experts have said that the amount of diesel coming from Russia under Trump’s deal cannot make up for the vast volumes the world received from the Middle East via the Strait of Hormuz before the U.S. and Israel first attacked Iran on Feb. 28.