(FILES) In this file photo taken on December 24, 2018, US President Donald Trump speaks on the telephone as he answers calls from people calling into the NORAD Santa tracker phone line in the State Dining Room of the White House in Washington, DC. - US President Donald Trump vowed Tuesday, December 25, 2018, he would not reopen the government until he gets $5 billion to fund his border wall, as the partial government shutdown dragged into a fourth day. Trump's demand for a physical barrier on the US-Mexico border -- a pillar of his election platform -- has been rejected by Democrats and some Republicans. In retaliation, Trump refused last week to sign a wider spending bill, temporarily stripping funding from swaths of the government. (Photo by SAUL LOEB / AFP)