President of Brazil Dilma Rousseff speaks at the 70th session of the General Assembly, at the United Nations headquarters in New York, the , on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

President of Brazil Dilma Rousseff waits to speak at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua 

President of Brazil Dilma Rousseff speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua 

UN General Assembly President Mogens Lykketoft (C) speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua 

US President (bottom) speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua 

US President Barack Obama (L) waits to speak at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua 

US President Barack Obama speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua 

US President Barack Obama speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua 

US President Barack Obama speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua 

US President Barack Obama speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

Egypt's President Abdel Fattah al-Sisi (R-Front) speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

President of South Africa Jacob Zuma speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

President of South Africa, Jacob Zuma (R) waits to address the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

Swiss President Simonetta Sommaruga (R, front) speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

Swiss President Simonetta Sommaruga speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

President of South Africa Jacob Zuma (R, front) speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

Egypt's President Abdel Fattah al-Sisi speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

Egypt's President Abdel Fattah al-Sisi (R) waits to address the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday.  Photo: Xinhua

South African President Jacob Zuma speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua

Egyptian President Abdel Fattah al-Sisi speaks at the 70th session of the United Nations General Assembly, at the United Nations headquarters in New York, the United States, on Sept. 28, 2015. The general debate of the 70th session of the United Nations General Assembly kicked off at the general assembly hall of the UN headquarters in New York on Monday. Photo: Xinhua