Skip to 50:00 to get to the press conference.

Obama said that he and his various advisors feel that Syria must be attacked in response to their usage of chemical weapons. He specified that there would be no infantry sent to Syria, just a long distance strike of "limited duration and scope". Congress will hold a vote on whether or not to approve the attack. The President has the authority to order the strike, with or without the approval of Congress.

*edit: see reply