UN 70th General Assembly live
US President Barack Obama speaks at the United Nations General Assembly Reuters

US president Barack Obama and his Russian and Chinese counterparts Vladimir Putin and Xi Jinping are three of more than 150 heads of state from all over the world due to take the stage at the UN general assembly in New York.

Significantly, the leaders of the three global superpowers are to address the 70th session of the UN's annual debate in rapid succession on the first day of the diplomatic shindig, which is to be opened this morning at 9am local time by UN secretary general Ban Ki-moon, whose annual report is to be followed by a keynote speech from the assembly president, Mogens Lykketoft of Denmark.

As per tradition, the head of state of Brazil, Dilma Rousseff, will be the first national leader to speak. She will be followed by 36 other heads of state, range between monarchs, presidents and prime ministers. Among them are Iranian president Hassan Rouhani, France's François Hollande, Cuba's Raúl Castro, Egypt's Abdel Fattah Al Sisi, Zimbabwean dictator Robert Mugabe and Argentina's Cristina Fernández de Kirchner.

The civil war in Syria and the related refugee crisis in Europe, the Iranian nuclear deal and the tensions in Ukraine are expected to be hot topics. Many leaders have already taken part in a run-up three-day UN event on sustainable development. The General Assembly concludes its works on 3 October.

You can watch all the addresses live here: