This year's UN General Assembly meeting in New York, which kicks off Wednesday, boasts a few firsts. 

Hu Jintao will be the first Chinese head of state to attend in 40 years.  It'll also be Libyan President Muammar Gaddafi's first visit to the United States since taking power in 1969. 

On Thursday, President Barack Obama will be the first U.S. president to chair a special UN Security Council session. 

Beyond the usual pomp and circumstance, past gatherings have rarely yielded in any major diplomatic breakthroughs. 

The Obama administration hopes this year will be different. 

During the presidential campaign, Obama said he wanted to use the UN to rebuild global alliances and partnerships.  

Still, a lot has changed in America and the world since then.

The question now is can the president use some of his personal popularity abroad to shape some of the complex foreign policy challenges?

Nuclear proliferation, Middle East peace, climate change and financial regulation are all concerns.

"The expectations of the president domestically as well as internationally are almost off the charts," said Tom Weiss, author of What's Wrong with the UN.

The president will address the assembly Wednesday evening.

Some of the other notable leaders also expected to speak include Iran's president Mahmoud Ahmadinejad and Libya's Colonel Gaddafi.