French President Francois Hollande, flanked by French Minister for Higher Education and Research Thierry Mandon, French Education Minister Najat Vallaud-Belkacem and French Prime Minister Manuel Valls stand among students as they observe a minute of silence at the Sorbonne University in Paris to pay tribute to victims of Friday's Paris attacks, France, November 16, 2015 (Reuters)

French President Francois Hollande, center, stands among students during a minute of silence in the courtyard of the Sorbonne University in Paris, Monday, Nov. 16 2015 (AP)

French and U.S. flags fly at half mast outside the New York Stock Exchange in honor of the victims of the terrorist attacks in Paris last week on November 16, 2015 in New York City (AFP)

Traders observe a moment of silence before the opening bell on the floor of the New York Stock Exchange, Monday, Nov. 16, 2015, in the wake of the terrorist attacks in Paris on Friday (AP)

People stand in Trafalgar Square, London, during a minute's silence to mark the victims of Friday's terror attacks in the French capital Monday Nov. 16, 2015 (AP)

French Ambassador to London Sylvie Bermann, centre, left, and Britain's Home Secretary Theresa May, centre, right, stand inside the French Embassy in London during a minute's silence across Europe to mark the victims of Friday's attacks in the French capital Monday Nov. 16, 2015 (AP)

French President Francois Hollande, center, flanked by French Prime Minister Manuel Valls, right, and French Education Minister Najat Vallaud-Belkacem, center left, stands among students during a minute of silence in the courtyard of the Sorbonne University in Paris, Monday, Nov. 16 2015 (AP)

A man holds a placard reading "I am the living together" as people gather after observing a minute of silence to pay tribute to victims of the attacks claimed by Islamic State, on November 16, 2015 at the Place de la Republique in Paris (AFP)

French national and European Union flags are lowered at half staff over French embassy as embassy personnel and members of French community observe a minute of silence in Ankara, Turkey, Monday, Nov. 16, 2015 (AP)

A minute of silence in respect for the victims of recent Paris terror attacks, with France's ambassador to Portugal Jean-Francois Blarel, center left, stands with Portuguese Prime Minister Pedro Passos Coelho, centre, former President of the European Council Herman Van Rompuy, center right, and the ambassadors of the EU countries during a minute of silence ceremony for the victims of the Paris attacks Monday, Nov. 16 2015, at Lisbon's Sao Bento Palace, the premier's official residence (AP)

Dutch Ministers and Secretaries of State observe, on behalf of the Cabinet, a minute of silence in tribute to the victims of the attacks claimed by Islamic State which killed more than 120 people and left more than 350 injured on November 13 in Paris at the French Embassy in The Hague on November 16, 2015 (AFP)

Hungarian representatives take part in a minute of silence in the Parliament in Budapest, Hungary, November 16, 2015 (Reuters)

(From L to R) European Union leaders Spanish President Mariano Rajoy, German Chancellor Angela Merkel, European Council President Donald Tusk, French Foreign minister Laurent Fabius, European Commission President Jean-Claude Juncker, British Prime Minister David Cameron, Italian Prime Minister Matteo Renzi, observe a minute of silence in tribute to the victims of Paris attacks, during the G20 Summit on November 16, 2015 in Antalya (AFP)

Pupils attend a minute of silence on November 16, 2015 in a Tallinn school to honor the victims of Paris terror attacks (AFP)

People observe a minute of silence on November 16, 2015 in front of the French Embassy in Zabreb, to pay tribute to victims of Paris attacks claimed by Islamic State (AFP)

French nationals attend a memorial tribute to the victims of Friday's attacks in Paris, at the French Embassy in Beijing, China, November 16, 2015 (Reuters)

In this photo provided by Alquier Communication, suspended UEFA president Michel Platini, centre, CEO of UEFA Events SA, Martin Kallen, left, UEFA Deputy General Secretary, Theodore Theodoridis, right, and UEFA staff members observe a minute of silence in honor of the victims of the Paris attack in a ceremony at the headquarters of European soccer's governing body in Nyon, Switzerland, Monday, Nov. 16, 2015 (AP)

People stand still during a minute of silence at the Brandenburg Gate in Berlin, Germany, Monday, Nov. 16, 2015, to honor the victims of the terrorist attacks in France on Friday, Nov. 13, 2015 (AP)

Spanish deputees observe a minute of silence outside the "Las Cortes" (Spanish Congress) in Madrid on November 16, 2015 to pay tribute to victims of Paris attacks (AFP)

Members of some Spanish trade unions hold up banners that reads, ''November 16. We Are All Paris'' as they stand during a minute of silence for the victims in Friday's attacks in Paris in Pamplona, northern Spain, Monday, Nov. 16, 2015 (AP)

Prince Albert II of Monaco, second left, his wife Princess Charlene, and his sister Princess Caroline of Hanover, observe a minute's silence in the Monaco palace, Monday, Nov. 16, 2015, as they pay their respects to the victims of Friday night's terror attacks in Paris (AP)

People observe a minute of silence on November 16, 2015 in front of the French embassy at Piazza Farnese in Rome, to pay tribute to victims of PAris attacks claimed by Islamic State (AFP)

The mayor of the Brussels Molenbeek neighborhood Francoise Schepmans, 2nd left, together with other officials hold a minute of silence in remembrance of the Paris terror attacks victims, in Brussels on Monday, Nov. 16, 2015 (AP)