First, diesel fuel and now, potash. U.S. President Donald Trump’s wheeling and dealing has run up against realities of the physical economy. The shocking rise in the cost of diesel, at the core of both transportation and agriculture, has concerned the president a lot more than the damage he has done, and may still do, to Iran. The economic ramifications already threaten to completely dismantle his constituency and create an electoral disaster. Now, potash joins the list.

Canada has been a major supplier to the United States of potash. Saskatchewan-based Nutrien Ltd. and U.S.-based Mosaic Co. (Cargill) dominate potash production in North America, but Trump’s trade war with Canada has thrown the supply into question. And, before the day was over, Trump’s public assurance that the crisis over fertilizer—based upon losing Canada’s exports of potash—was not really a problem, came crashing down.

Trump posted today: “The United States is working on a massive Deal with respect to the purchase of Potash from Belarus. The pricing would be for substantially less than we are currently paying to Canada, very good news for our Farmers and Ranchers.” While this claim is already sketchy, given Canada’s ability to send potash to the U.S. at a significantly lower cost than what it takes Belarus to ship their potash here, it quickly got worse.

Shortly after Trump’s announcement, Belarus’s President Alexander Lukashenko told reporters on TodayPress TV: “Even if we wanted to supply potash to other destinations, to Western markets, we simply do not have the volumes for that—all of it has already been sold under contract.”