A staff of Geneva Ports Francs (Free Ports) walks in a warehouse during a media visit in Geneva, Switzerland September 6, 2016. Picture taken September 6, 2016. REUTERS/Denis Balibouse

The Geneva Ports Francs (Free Ports) building is pictured in Geneva, Switzerland September 6, 2016. REUTERS/Denis Balibouse

A paper showing percentages of free ports usage is seen during an interview with David Hiler, chairman of Geneva Ports Francs (Free Ports), in Geneva, Switzerland September 6, 2016. REUTERS/Denis Balibouse

A staff of Geneva Ports Francs (Free Ports) handles boxes in the wine warehouse during a media visit in Geneva, Switzerland September 6, 2016. REUTERS/Denis Balibouse

Canada's Prime Minister Justin Trudeau (R) shakes hands with Chinese Premier Li Keqiang during a meeting on Parliament Hill in Ottawa, Ontario, Canada, September 22, 2016. REUTERS/Chris Wattie

U.S. Defense Secretary Ash Carter (L) and Chairman of the Joint Chiefs of Staff Joseph Dunford testify before a Senate Armed Services Committee hearing on National Security Challenges and Ongoing Military Operations on Capitol Hill in Washington, U.S., September 22, 2016. REUTERS/Yuri Gripas

U.S. Defense Secretary Ash Carter testifies before a Senate Armed Services Committee hearing on National Security Challenges and Ongoing Military Operations on Capitol Hill in Washington, U.S., September 22, 2016. REUTERS/Yuri Gripas

U.S. Defense Secretary Ash Carter (L) and Chairman of the Joint Chiefs of Staff Joseph Dunford testify before a Senate Armed Services Committee hearing on National Security Challenges and Ongoing Military Operations on Capitol Hill in Washington, U.S., September 22, 2016. REUTERS/Yuri Gripas