US President Donald Trump (front row C) reacts as he stands by (front row from L) Portuguese Prime Minister Antonio Costa, Greek Prime Minister Alexis Tsipras, Hungary's Prime Minister Viktor Orban, Britain's Prime Minister Theresa May, (back row from L Romanian President Klaus Werner Iohannis, Slovakia's President Andrej Kiska and Iceland's Prime Minister Bjarni Benediktsson, during a family picture during the NATO (North Atlantic Treaty Organization) summit at the NATO headquarters, in Brussels, on May 25, 2017. / AFP PHOTO / Mandel NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)
WASHINGTON, DC - MAY 02: U.S. President Donald Trump speaks while standing with the U.S. Air Force Falcons football team before presenting them with the Commander-in-Chief trophy, in the Rose Garden at the White House, on May 2, 2017 in Washington, DC. (Photo by Mark Wilson/Getty Images)
SARASOTA, FL - NOVEMBER 07: Republican presidential nominee Donald Trump holds up a rubber mask of himself during a campaign rally in the Robarts Arena at the Sarasota Fairgrounds November 7, 2016 in Sarasota, Florida. With less than 24 hours until Election Day in the United States, Trump and his opponent, Democratic presidential nominee Hillary Clinton, are campaigning in key battleground states that each must win to take the White House. (Photo by Chip Somodevilla/Getty Images)
US President Donald Trump (R) welcomes Chinese President Xi Jinping (L) to the Mar-a-Lago estate in West Palm Beach, Florida, on April 6, 2017. / AFP PHOTO / JIM WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)
BAGHDAD, IRAQ - APRIL 03: In this handout provided by the Department of Defense (DoD), Jared Kushner, Senior Advisor to President Donald J. Trump, meets with military officials after arriving on April 3, 2017 in Baghdad, Iraq. (Photo by Dominique A. Pineiro/DoD via Getty Images)
TAJI, IRAQ - APRIL 12: U.S. Army trainers watch as an Iraqi recruit fires at a military base on April 12, 2015 in Taji, Iraq. U.S. forces, currently operating in 5 large bases throught the country, are training thousands of Iraqi Army combat troops, trying to rebuild a force they had origninally trained before the U.S. withdrawal from Iraq in 2010. Members of the U.S. Army's 5-73 CAV, 3BCT, 82nd Airborne Division are teaching members of the newly-formed 15th Division of the Iraqi Army, as the Iraqi government launches offensives to try to recover territory lost to ISIS last year. (Photo by John Moore/Getty Images)
National Security Adviser Michael Flynn, left, stands with K. T. McFarland, and Michael Anton during the daily news briefing at the White House, in Washington, Wednesday, Feb. 1, 2017. Flynn said the administration is putting Iran "on notice" after it tested a ballistic missile. (AP Photo/Carolyn Kaster)
ZAGAN, POLAND - JUNE 18: A soldier of the Polish Army sits in a tank as a NATO flag flies behind during the NATO Noble Jump military exercises of the VJTF forces on June 18, 2015 in Zagan, Poland. The VJTF, the Very High Readiness Joint Task Force, is NATO's response to Russia's annexation of Crimea and the conflict in eastern Ukraine. Troops from Germany, Norway, Belgium, Poland, Czech Republic, Lithuania and Belgium were among those taking part today. (Photo by Sean Gallup/Getty Images)
TOPSHOT - Demonstrators protest President Donald Trump's executive immigration ban at O'Hare International Airport on January 29, 2017 in Chicago, Illinois.
US President Trump signed the controversial executive order that halted refugees and residents from predominantly Muslim countries from entering the United States. / AFP / Joshua LOTT (Photo credit should read JOSHUA LOTT/AFP/Getty Images)
WASHINGTON, DC - FEBRUARY 02: (AFP OUT) U.S. President Donald Trump meets with executives and union representatives from the Harley Davidson company at the White House on February 2, 2017 in Washington, DC. At the end of the photo opportunity, Trump said "nothing is off the table" in relation to current disagreements between the U.S. and Iran. (Photo by Win McNamee/Getty Images)
WASHINGTON, DC - JANUARY 20: U.S. President-elect Donald Trump arrives on the West Front of the U.S. Capitol on January 20, 2017 in Washington, DC. In today's inauguration ceremony Donald J. Trump becomes the 45th president of the United States. (Photo by Chip Somodevilla/Getty Images)
WASHINGTON, DC - MAY 11: U.S. President Barack Obama pauses as he speaks during an event to recognize emerging global entrepreneurs May 11, 2015 at the South Court Auditorium of Eisenhower Executive Office Building in Washington, DC. Entrepreneurs from across the U.S. and around the world participated, ahead of President Obamas travel to the Global Entrepreneurship Summit in Kenya this summer, in the event which focused on investing in women and young entrepreneurs. (Photo by Alex Wong/Getty Images)
HAMBURG, GERMANY - DECEMBER 28: Participant hold their laptops in front of an illuminated wall at the annual Chaos Computer Club (CCC) computer hackers' congress, called 29C3, on December 28, 2012 in Hamburg, Germany. The 29th Chaos Communication Congress (29C3) attracts hundreds of participants worldwide annually to engage in workshops and lectures discussing the role of technology in society and its future. (Photo by Patrick Lux/Getty Images)
MOBILE, AL - DECEMBER 17: President-elect Donald Trump speaks during a thank you rally in Ladd-Peebles Stadium on December 17, 2016 in Mobile, Alabama. President-elect Trump has been visiting several states that he won, to thank people for their support during the U.S. election. (Photo by Mark Wallheiser/Getty Images)
