The United States, Canada and Mexico return to the negotiating table Tuesday for talks on rewriting the three-nation trade agreement, one day after President Trump applied tariffs that will hurt Mexico, among other countries. NAFTA talks were already complicated by tariffs that the United States imposed on Canadian paper two weeks ago. Canadian officials called those “unfair and unwarranted.” Mexico is one of the biggest exporters of washing machines to the United States. Its economy ministry vowed to use “all legal resources available in response to the U.S. decision.” The three countries are meeting in Montreal for their sixth round of NAFTA talks. They’ve made no progress on divisive issues, and the Trump administration’s major proposals, particularly one on auto manufacturing, are unacceptable to Canada and Mexico. Trump has repeatedly threatened to withdraw the United States from the trade agreement if he can’t get a better deal for U.S. workers. One of his counterparts, Canadian Prime Minister Justin Trudeau, is trying to pull Trump back from the brink.