MINNEAPOLIS (AP) — A U.S.-Canada trade dispute has spread to Minnesota, where officials say 19 dairy farms are affected.

Lucas Sjostrom, executive director of the Minnesota Milk Producers Association, said Wednesday that 19 Minnesota producers are among the 70 to 75 initially reported as all being from Wisconsin.

Canada recently imposed duties on ultra-filtered milk, a concentrate used to make cheese. It was duty free until Canadian producers complained. The affected farms supplied Grassland Dairy Products of Greenwood, Wisconsin, which lost its market for the product. Many of those farms may now be forced out of business.

Minnesota Gov. Mark Dayton wrote to President Donald Trump last week urging him to uphold free trade.

Trump said in Wisconsin Tuesday that he'll work on a solution.

Some New York producers are also affected.

More From KROC-AM