When the U.N. General Assembly session covenes Monday, the session will mark the organization's 70th anniversary as world leaders meet at the U.N. headquarters in New York to discuss development goals. This year, the annual general debate comes as countries grapple with how to solve the global refugee crisis and the Syrian conflict.

Secretary-General Ban Ki-moon encouraged the 193-member body to look back at the history of the U.N. and all that has been accomplished during the annual meeting as they proceed to discuss complicated issues.

“The Charter’s principles have stood the test of time, and the United Nations can look back on a record of achievement,” Ban said. “At the same time, we know that suffering remains widespread across the world. My thoughts today are especially with the people of Syria -- those inside the country facing terrible violence, and those who have fled, desperately seeking a safe haven and a better life.”

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Each annual general assembly provides a forum for discussion of a wide range of international issues that fall under the umbrella of the U.N. Charter. It meets in regular session from September to December each year, and thereafter as necessary. This session, the international community faces challenges such as how to contain and fight militant groups, including the Islamic State group in Syria and Iraq.

“The U.N. and its member states have a strong obligation to work together to end the catastrophic wars and conflicts -- not least in and around Syria," said Mogens Lykketoft, president of the 70th session of the General Assembly. "And we will have to act here and now to address the huge and explosive refugee crises resulting from ongoing conflicts -- and to protect the human rights of all refugees.”

Sustainable development will also be among the topics prioritized during the session. Leaders plan to set an agenda as the first step in a comprehensive sustainability plan, which will be addressed again in Paris this December during the 2015 U.N. Climate Change Conference. 

“The summit, of course, marks only the beginning,” Lykketoft said. “There is an urgent need for action right across the three pillars of the U.N. and ample opportunities to do so during this session. … An ambitious and universal climate agreement is an absolute must and the first real test of the world community’s ability to deliver the necessary policy tools for sustainable development.”

You can view the live stream the session's opening and meetings online on PBS here.