Thousands of additional active duty US troops are being ordered to the southern US border with Mexico, just two days after President Donald Trump mandated that the US military step up its presence there,

A rare winter storm churned across the U.S. Gulf Coast on Tuesday, bringing heavy snow, ice and wind gusts to a region where flurries are unusual, while much of the United States remained in a deep freeze.

Most of the United States is being assailed with extreme winter weather this week as Arctic air blasts south from Canada, snow tracks up the Northeast coast and a potentially crippling winter storm takes aim at the South.