U.S. President Barack Obama addresses the 39th Annual Congressional Hispanic Caucus Institute Public Policy Conference and Annual Awards Gala, in Washington, U.S., September 15, 2016. REUTERS/Mary F. Calvert

Iraqi Prime Minister Haider al-Abadi addresses the media during a joint news conference with Iraqi Kurdish President Massoud Barzani in Arbil, April 6, 2015. REUTERS/Azad Lashkari/File Photo

Nigeria's President Muhammadu Buhari attends the opening session of the second Regional Security Summit in Abuja, Nigeria May 14, 2016. REUTERS/Afolabi Sotunde

Colombia's President Juan Manuel Santos (C) and Costa Rica's President Luis Guillermo Solis (R) look at a map of nautical limits between Ecuador, Colombia, and Costa Rica in Puerto Ayora, Ecuador September 9, 2016. REUTERS/Guillermo Granja

Traders work on the floor of the New York Stock Exchange (NYSE) in New York City, U.S., September 15, 2016. REUTERS/Brendan McDermid

The EgyptAir plane scheduled to make the following flight from Paris to Cairo, after flight MS804 disappeared from radar, taxies on the tarmac at Charles de Gaulle airport in Paris, France, May 19, 2016. REUTERS/Christian Hartmann

Britain Football Soccer - Chelsea v Liverpool - Premier League - Stamford Bridge - 16/9/16 Liverpool's James Milner clears Reuters / Dylan Martinez Livepic

The EgyptAir plane scheduled to make the following flight from Paris to Cairo, after flight MS804 disappeared from radar, taxies on the tarmac at Charles de Gaulle airport in Paris, France, May 19, 2016. REUTERS/Christian Hartmann