Prime Minister Justin Trudeau announced on March 18 that Canada and the United States have agreed to temporarily limit all non-essential travel to the Canada-U.S. Border that will come into effect tonight at midnight. Bilateral economic relations, which were already considerable, have developed considerably over the past three decades, with trade relations governed by the 1989 U.S.-Canada Free Trade Agreement and, since 1994, the North American Free Trade Agreement (NAFTA). Canada is the second largest trading partner of the United States, with cross-border trade between two countries and services of more than $1.6 billion per day in 2017. The United States is also Canada`s largest investor, while Canada is a major source of foreign direct investment in the United States. Countries have a highly integrated energy market, with Canada being the largest supplier of energy imports to the United States and the largest recipient of U.S. energy exports. On April 11, 1908, in accordance with Article IV of the 1908 Treaty, the United Kingdom and the United States agreed on the border between the United States and the Dominion of Canada, from the Atlantic Ocean to the Pacific Ocean, to measure and delineate the Canada-U.S. border across the St. Lawrence River and the Great Lakes using modern measurement techniques.
  In 1925, the temporary mission of the International Border Commission became permanent for maintaining the elevation and mapping of the border; The conservation of border monuments and buoys; and hold the border without brush and vegetation for 6 meters (20 ft). This „limit view“ extends for 3 meters (9.8 ft) on either side of the line.  In recent years, Canadian officials have drawn attention to drug, cigarette and firearm smuggling from the United States, while U.S. officials have made complaints about drug trafficking in Canada. In July 2005, law enforcement arrested three men who had built a 110-metre tunnel under the B.C.-Washington border for marijuana use, the first of its kind known at the border.  From 2007 to 2010, 147 people were arrested on the grounds of a bed and breakfast in Blaine, Washington, but officers estimate they took only about 5% of the smugglers.  Until October 2015, the conifer trade was governed by a seven-year agreement (SLA) concluded in 2006, which was extended by two years until 2015 and limited Canadian exports to the United States. Under a complex formula, the United States has authorized unlimited imports of Canadian wood if market prices have remained above a certain level; when prices fell below this level, Canada imposed export taxes and/or quotas. In addition, the United States repatriated much of the tariffs it had collected as a result of previous aid-for-trade cases to Canada.