Obama also said in an NBC interview that he did not rule out arming Libyan rebels as they seek to make territorial gains and overthrow Qaddafi.
On March 29, a Western-led conference on the future of Libya agreed to set up a contact group to lead international efforts to stabilize the North African country and hold Qaddafi "accountable" for his actions.
British Foreign Secretary William Hague said at the end of the conference in London that the newly established Libya Contact Group would be chaired by the Gulf state of Qatar, where it will also hold its first meeting "as soon as possible."
Representatives from more than 40 countries and international organizations attended the conference.
Meanwhile, rebel forces, which had made big advances westwards amid coalition air strikes against Qaddafi's positions, were reportedly repelled on March 30 by government tanks and rockets from around Qaddafi's birthplace of Sirte.
Rebels were forced to retreat from the town of Nawfaliya, 150 kilometers from Sirte, to the coastal town of Bin Jawad further east.
compiled from agency reports