SEOUL—In a historic trade agreement that President Donald Trump touted as a major win for an American farmer, China reportedly agreed Thursday to purchase 11 U.S. soybeans.

“I am extremely honored that President Xi has authorized China to begin the purchase of this unprecedented amount of American-grown soybeans—not merely nine or 10 beans, but 11 whole, intact beans,” Trump said at a highly anticipated summit in South Korea with his Chinese counterpart, moments after handing President Xi Jinping a small handful of dry soybeans from his pants pocket in exchange for 2 cents worth of aluminum.