PALM BEACH, Florida: President Donald Trump says he is likely to shut down America’s southern border next week unless Mexican authorities immediately halt all illegal immigration. Such a severe move could hit the economies of both countries, but the president emphasized, “I am not kidding around.” Trump says that “could mean all trade” with Mexico. Trump has been promising for more than two years to build a long, impenetrable wall along the border to stop illegal immigration, though Congress has been reluctant to provide the money he needs. In the meantime, he has repeatedly threatened to close the border. But this time, with a new surge of migrants heading north, he gave a definite timetable.