The European Union is pushing back against the House-approved measure to strengthen sanctions against Russia, arguing “America first cannot mean that Europe’s interests come last.”

“The U.S. bill could have unintended unilateral effects that impact the EU’s energy security interests,” Jean-Claude Juncker, the European Commission president, said in a statement. “This is why the Commission concluded today that if our concerns are not taken into account sufficiently, we stand ready to act appropriately within a matter of days.”

The U.S. House of Representatives approved the measure 419-3 on Tuesday, paving the way for the Senate to approve a similar proposal, which it is expected to do, setting up a showdown with the White House. The measure is especially controversial because not only does it tighten sanctions against Russia for its election interference and invasion of Crimea, but it mandates that the president consult with it before waiving the punitive measures; at present the president can waive sanctions determined to be detrimental to U.S. interests.

President Trump has not said whether he’ll sign the measure, but he sees friendly relations with Russia as an important cornerstone of U.S. foreign policy. The approval of the House measure comes amid scrutiny of the Trump campaign’s ties to Russian officials in the run up to the 2016 presidential election. U.S. intelligence agencies say Russia interfered in the election in order to boost Trump, though it’s unclear if Moscow’s efforts succeeded. Trump’s equivocation over the issue has led to more speculation about his campaign’s ties to Russian officials—links that are being investigated by the Justice Department and congressional committees.

Russia also pushed back against the House vote, with Senator Alexei Pushkov, who previously headed the Duma’s international affairs committee, calling it “a new phase in the confrontation.” At the Kremlin, Dimitri Peskov, President Vladimir Putin’s spokesman, said there would be no announcement until the U.S. Senate and Trump acted. He called the reaction by Russian lawmakers “quite understandable.”

“We are talking about extremely unfriendly manifestations, so the reaction is obvious,” he said.

European reaction to the House vote can be best understood through the prism of the joint U.S.-EU sanctions imposed on Russia in 2014, following its invasion of Ukraine’s Crimea. EU relies heavily on Russia for its energy needs, and European companies have vast business dealings with Russian ones. The previous set of sanctions took these realities into account. The House-approved measure, which also includes sanctions on Iran and North Korea, targets Russia’s mining, shipping, defense, and other sectors where European companies have extensive links. The bill would also impose penalties on joint European-Russian energy projects;  the Nord Stream 2 pipeline from Russia to Germany is seen as particularly vulnerable.

Earlier this week, the Financial Times reported that the EU was drafting possible countermeasures against the U.S., including seeking a written assurance from the Trump administration on the issue, as well as, in the words of a European memo seen by the FT, “WTO-compliant retaliatory measures.”

It’s unclear when the Senate will vote on the measure—and how much their version will differ from that passed by the House. Senators voted 98-2 to approve a previous version of the bill.