Security Council OKs Nonproliferation Resolution; Obama Chairs Session

For the first time in the United Nations Security Council's history, an American president is in the chairman's seat.

President Barack Obama just opened a session at which the leaders are to discuss the issues of nuclear disarmament and nonproliferation.

He's been joined at the session by a who's who of world leaders, including British Prime Minister Gordon Brown and Russian President Dmitry Medvedev.

The U.N. is webcasting the session here (scroll down its "live schedule" and click on "channel 8").

We'll update this post with highlights. Click your "refresh" button in order to see our latest additions.

If you're interested in reading through lots of information about the Security Council and its history, the U.N. has quite a bit here.

Update at 10:25 a.m. ET. The White House has sent reporters a "fact sheet" about the resolution (if you click on the box in the top right corner you can "toggle" to a full screen and then expand the document):

White House on U.N. Resolution 1887

Update at 9:56 a.m. ET: Here's audio of the president's opening statement and the vote:

Update at 9:45 a.m. ET: Speaking about a world free of nuclear weapons, Obama says "we harbor no illusions ... we know there are plenty of cynics and setbacks that prove their point."

But "we will leave this meeting with a renewed determination to achieve this goal," Obama says.

Update at 9:40 a.m. ET: By a 15-0 vote, the Security Council just approved Resolution 1887. As Reuters reports, that is "a U.S.-drafted resolution ... calling on nuclear weapons states to scrap their deadly arsenals."