President Barack Obama on Friday authorized the U.S. military to deploy up to 1,500 additional troops to help train and advise Iraqi and Kurdish forces fighting Islamic State militants, the White House said. The new troops will support the roughly 1,600 U.S. personnel already in Iraq, under what the Pentagon calls Operation Inherent Resolve. The U.S. has steadily ramped up its mission in Iraq since Obama announced in June that 300 military advisors would be sent back to the country, three years after American forces withdrew.