When Dayana Castro heard that the U.S. asylum appointment she waited over a year for was canceled in an instant, she had no doubt: She was heading north any way she could. The 25-year-old migrant, her husband and their 4- and 7-year-old children had nothing left at home in Venezuela.

President Donald Trump’s plans to seal the U.S.-Mexico border and conduct mass deportations might soon run into a major roadblock: Mexico and the countries where the immigrants come from might not accept some of them back.

The president's pledge to slap 25 percent tariffs on Canada and Mexico could see the prices of goods soar for U.S. consumers.