Millennials may need a new superfood to top their toast soon.

President Donald Trump’s threats to shut down the U.S.-Mexico border this week would significantly impact produce availability and pricing in the United States, especially avocados.

“You couldn’t pick a worse time of year because Mexico supplies virtually 100 percent of the avocados in the U.S. right now. California is just starting and they have a very small crop, but they’re not relevant right now and won’t be for another month or so,” Mission Produce president and CEO Steve Barnard said to Reuters.

He estimates that the United States would run out of avocados in three weeks if imports from Mexico were halted.

Mission Produce is the world’s top avocado grower and distributor, according to Reuters.

Nearly half of all imported U.S. vegetables and 40 percent of imported fruit are grown in Mexico, according to the United States Department of Agriculture. Besides avocados, the most heavily impacted imports include tomatoes, cucumbers, blackberries and raspberries.

Trump said on Friday that there was a “very good likelihood” of closing the border this week if Mexico did not stop immigrants from reaching the United States. Reuters reported that a complete shutdown would disrupt millions of legal border crossings in addition to asylum seekers, as well as billions of dollars in trade, about $137 billion of which is in food imports.