French Ambassador to the United States Gerard Araud (L) listens as US President Barack Obama speaks about the attack in Nice, France while addressing ambassadors to the United States during reception in the East Room of the White House July 15, 2016 in Washington, DC. Obama strongly condemned a "repugnant" proposal by a top Republican to test every Muslim living in the United States and deport whoever believes in sharia law, following the deadly truck attack in Nice. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

US President Barack Obama speaks about the truck attack in Nice, France while addressing ambassadors to the United States during reception in the East Room of the White House July 15, 2016 in Washington, DC. Obama strongly condemned a "repugnant" proposal by a top Republican to test every Muslim living in the United States and deport whoever believes in sharia law, following the deadly truck attack in Nice. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

US President Barack Obama speaks about the truck attack in Nice, France while addressing ambassadors to the United States during reception in the East Room of the White House July 15, 2016 in Washington, DC. Obama strongly condemned a "repugnant" proposal by a top Republican to test every Muslim living in the United States and deport whoever believes in sharia law, following the deadly truck attack in Nice. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

US President Barack Obama speaks about the truck attack in Nice, France while addressing ambassadors to the United States during reception in the East Room of the White House July 15, 2016 in Washington, DC. Obama decried the deadly truck attack in Nice as a "tragic and appalling" on freedom and pledged firm US support for France. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

US President Barack Obama speaks about the truck attack in Nice, France while addressing ambassadors to the United States during reception in the East Room of the White House July 15, 2016 in Washington, DC. Obama decried the deadly truck attack in Nice as a "tragic and appalling" on freedom and pledged firm US support for France. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

French Ambassador to the United States Gerard Araud (C) watches as US President Barack Obama greets guests after addressing ambassadors to the United States during reception in the East Room of the White House July 15, 2016 in Washington, DC. Obama spoke to the diplomatic corp calling the deadly truck attack in Nice as a "tragic and appalling" on freedom and pledged firm US support for France. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

US President Barack Obama is seen in a mirror as he speaks about the attack in Nice, France while addressing ambassadors to the United States during reception in the East Room of the White House July 15, 2016 in Washington, DC. Obama decried the deadly truck attack in Nice as a "tragic and appalling" on freedom and pledged firm US support for France. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

WASHINGTON, DC - JULY 15: US President Barack Obama talks about yesterday's terrorist attack in Nice, France that killed 84 people, during a reception for the Diplomatic Corps in the East Room at the White House on July 15, 2016 in Washington, DC. (Photo by Mark Wilson/Getty Images)