While the White House is encouraging companies to buy domestically made parts, that’s not always possible.

In a recent interview, Ford Motor Co. CEO Jim Farley warned that his company must import fasteners and other parts to assemble its vehicles, Fortune.com reports.

“We have to import certain parts,” Farley said. “A lot of parts, like fasteners, washers, carpet … are just not available. We can’t even buy those parts here.”

And even when some parts are available from U.S. suppliers, it makes more economic sense to use imports to keep retail prices competitive, he added. Between 20% and 25% of the parts used in the best-selling F-150 are imported.

“The affordability of parts is a really important thing for America because we’ve got to keep the vehicles affordable,” he said. “Yes, we want to make them like Ford does in the U.S., but we also want to make the vehicles affordable that are built in the U.S.”

Two days after Farley's interview, Ford hiked the sticker prices for the three U.S. models it imports from Mexico by up to $2,000 each.