U.S. Republican presidential nominee Donald Trump and Mexico's President Enrique Pena Nieto walk out after finishing a press conference at the Los Pinos residence in Mexico City, Mexico, August 31, 2016. REUTERS/Henry Romero

Ellen Johnson-Sirleaf, President of the Republic of Liberia, addresses the 71st session of the United Nations General Assembly at the UN headquarters in New York on September 22, 2016. / AFP PHOTO / DOMINICK REUTERDOMINICK REUTER/AFP/Getty Images

Ellen Johnson-Sirleaf, President of the Republic of Liberia, addresses the 71st session of the United Nations General Assembly at the UN headquarters in New York on September 22, 2016. / AFP PHOTO / DOMINICK REUTERDOMINICK REUTER/AFP/Getty Images

Ellen Johnson-Sirleaf, President of the Republic of Liberia, sits in the Head of State Chair at the 71st session of the United Nations General Assembly at the UN headquarters in New York on September 22, 2016. / AFP PHOTO / DOMINICK REUTERDOMINICK REUTER/AFP/Getty Images

Paul Kagame, President of Rwanda waits to address the 71st session of the United Nations General Assembly at the UN headquarters in New York on September 22, 2016. / AFP PHOTO / DOMINICK REUTERDOMINICK REUTER/AFP/Getty Images

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

Paul Kagame, President of Rwanda addresses the 71st session of the United Nations General Assembly at the UN headquarters in New York on September 22, 2016. / AFP PHOTO / DOMINICK REUTERDOMINICK REUTER/AFP/Getty Images

Japan's Prime Minister Shinzo Abe (C), talks to Salvador Antonio Valdes Mesa, member of the Political Bureau of the Central Committee of the Communist Party of Cuba (CPC) and vice-president of the Council of State of Cuba (L) upon his arrival at the Jose Marti International Airport in Havana, Cuba, September 22, 2016. REUTERS/Alexandre Meneghini