UN General Assembly convenes this week

As the U.N. General Assembly convenes, it brings together all of its 192 member countries; this year, the U.S. is playing a larger role than usual. President Obama will attend some of the proceedings this week, starting with a summit on climate change. Then the General Assembly debate takes place, where a speech by Obama is scheduled to follow a speech by Libyan leader Muammar al-Qaddafi. We talk to BBC diplomatic correspondent Jonathan Marcus, who is in New York covering the events.