One of Apple's largest manufacturing partners is Hon Hai Precision Industry Co., Ltd, commonly known by the trade name Foxconn. Tonight, it's expected that Foxconn representatives, President Donald Trump, House Speaker Paul Ryan and Wisconsin Governor Scott Walker will announce a new Foxconn plant to be located in Wisconsin.
While Foxconn assembles iPhones and other products for Apple, it's unknown if Apple will have any part in the production at the plant. For example, several reports have said that the new plant would be used to create large-format TV displays, something that Apple doesn't currently sell nor have any plans to market.
On Tuesday, President Donald Trump made one of his patented tweets, saying that Apple was going to bring three "big, big, big" plants to the US. Since Apple doesn't assemble its own products, it's likely he was referring to the Foxconn facility and two other as-yet-unannounced plants.