The Trump administration is taking retaliatory action against Canada over a trade dispute, moving to impose a 20% tariff on softwood lumber that is typically used to build single-family homes.

In an interview Monday, Commerce Secretary Wilbur Ross said the tariff will be applied retroactively and imposed on Canadian exports to the U.S. of about $5 billion a year. He said the dispute centers on Canadian provinces that have been allegedly allowing loggers to cut down trees at reduced rates and sell them at low prices.