Coca-Cola has said it may have to increase its use of plastic in the U.S. if new tariffs on aluminum raise the cost of its drinks cans.

According to The Guardian, Coca-Cola’s chief executive, James Quincey, said during the company’s earning call February 11 that the drinks company imports aluminum for its cans from Canada, which is likely to be hardest hit by the 25% tariff on aluminum announced by President Donald Trump February 11, and scheduled to be introduc. As a result, it might be necessary to switch to plastic bottles, Quincey said.

However, he sought to play down the potential impact of tariffs on the business, saying packaging accounts for only a small portion of total costs.“I think we’re in danger of exaggerating the impact of the 25% increase in the aluminum price relative to the total system,” Quincey said on the call. “It’s not insignificant, but it’s not going to radically change a multibillion-dollar U.S. business, and packaging is only a small component of the total cost structure.”

Trump imposed 25% tariffs on foreign steel and aluminum imports in 2018 during his first term, although many drinks can makers won exemptions from penalties. This time, he has insisted that the tariffs would be enforced “without exceptions or exemptions.”

Coca-Cola has gradually increased the volume of its drinks sold in aluminum cans in recent years, as part of its sustainability targets.