The logo of the U.S. National Security Agency is seen during a visit by U.S. President George W. Bush to the agency's installation in Fort Meade, Maryland, January 25, 2006. Bush met with workers and made remarks on American national security at the high-security installation, which he last visited in 2002. REUTERS/Jason Reed - RTR18ZAD

Taro Aso, Japan's Deputy Prime Minister, attends a panel for the High-level Tax Symposium held in Chengdu in Southwestern China's Sichuan province, July 23, 2016. REUTERS/Ng Han Guan/Pool

An aerial photo taken though a glass window of a Taiwanese military plane shows the view of Itu Aba, which the Taiwanese call Taiping, at the South China Sea, March 2016. REUTERS/Ministry of Foreign Affairs

Cuba's President Raul Castro attends a meeting with Japan's Prime Minister Shinzo Abe (not pictured) at the Revolution Palace in Havana, Cuba September 22, 2016. REUTERS/Enrique de la Osa

Japan's Prime Minister Shinzo Abe and his wife Akie arrive at the Jose Marti International Airport in Havana, Cuba, September 22, 2016. REUTERS/Alexandre Meneghini

Japan's Prime Minister Shinzo Abe arrives at the Jose Marti International Airport in Havana, Cuba, September 22, 2016. REUTERS/Alexandre Meneghini

Japan's Prime Minister Shinzo Abe (C), talks to Cuban authorities upon his arrival at the Jose Marti International Airport in Havana, Cuba, September 22, 2016. REUTERS/Alexandre Meneghini

Cuban and Japanese flags are displayed on top of the airplane bringing Japan's Prime Minister Shinzo Abe upon his arrival at the Jose Marti International Airport in Havana, Cuba, September 22, 2016. REUTERS/Alexandre Meneghini