Economists have warned Donald Trump's plan to impose a 25 percent tariff on all products entering the United States from Mexico and Canada could have a dramatic impact on the economy of Texas, with one predicting it would cost 370,

Canada border is the longest in the world, stretching nearly 9,000km across land and water. Security on land is light; there are few walls or fences and in places it is marked by simple stone markers along residential streets.