The EU has pledged to buy $750 billion of energy from the U.S. in exchange for a lower rate tariff rate in its trade deal, but analysts say this is unrealistic.

The energy deal is a centerpiece of the trade agreement reached between Washington and Brussels on Sunday, which puts baseline U.S. tariffs at 15% for most European goods. The EU has agreed to buy $250 billion worth of U.S. oil, gas and nuclear fuels per year for three years, European Commission President Ursula von der Leyen said.

The European Union pledged to buy billions of dollars’ worth of energy resources from the United States. Experts say that’s unrealistic and could hurt Europe’s climate goals.