President Trump has threatened to close the U.S. border with Mexico if the southern neighbor doesn't not act to stop a migrant caravan.<br />The threat came in a tweet on Monday, in which he called many of the migrants "stone cold criminals" and appealed to Congress to fund his border wall. <br />It also came a day after American authorities closed the country's busiest southern border crossing and fired tear gas into crowds. <br />Mexican authorities said hundreds of those who were detained after Sunday's incident would be deported to their home countries.<br />Mexico City did not immediately respond to Trump's tweet. <br />
