Gen. Carter Ham spoke to reporters at a news conference a few hours before President Barack Obama said the United States would turn over leadership of the military operation to other, unnamed countries within a "matter of days, not weeks." Speaking at a news conference in Santiago, Chile, the president declined to be more specific.
Ham said the United States favors Libyan leader Moammar Gadhafi's ouster, but the international military effort has a more limited goal of establishing a no-fly zone over Libya and protecting civilians against massacre by forces loyal to the longtime ruler.
"Our military action is in support of an international mandate from the security council that specifically focuses on the humanitarian threat posed by Col. Gadhafi to his people," Obama said.
Coalition jets were patrolling the no-fly zone over Libya on Monday. The Pentagon said 12 more cruise missiles were fired at Libyan command, missile and air defense sites.
The Pentagon said the U.S.-led coalition has succeeded in scattering forces loyal to Gadhafi. This follows a weekend of punishing air attacks. Cruise missiles and precision bombs took out air craft hangars and tanks moving on the rebel stronghold of Benghazi.
The air assault has grounded Libyan planes and stopped ground advance on Benghazi, according to a U.S. general.
The allied strike even hit Gadhafi's compound in Tripoli. It's not known where Gadhadfi was at the time. Gadhafi is not a target of the campaign, a senior military official said Sunday, but he could not guarantee the Libyan leader's safety. Gadhafi has said he is prepared for a "long war."
Congressional Republicans, meanwhile, say they want the Obama Administration to answer questions about what the U.S. mission is in Libya, how it will be accomplished and how long the U.S. will be involved.
Top U.S. officials aren't predicting how long the military effort in Libya will last. But they said the U.S. intends to relinquish lead control of the mission over to a coalition - probably headed either by the French and British or by NATO.
"We expected in a matter of days to be able to turn over the primary responsibility to others," said Defense Secretary Robert Gates. "We will continue to support the coalition. We will be a member of the coalition; we will have a military role in the coalition, but we will not have the preeminent role."
Late Sunday, however, NATO's top decision-making body failed to agree on a plan to enforce the no-fly zone over Libya, although it did approve a military plan to implement a U.N. arms embargo.
Also in Libya on Tuesday, four New York Times reporters who were held for six days were freed. They crossed the border into Tunisia. Libya said they were captured last week by forces loyal to Gadhafi.
The Associated Press contributed to this report.