Defense Secretary Robert M. Gates acknowledged Wednesday that the international military enforcement of the no-fly zone over Libya lacks a clear ending, but President Obama said it "absolutely" will not lead to a U.S. land invasion.
They spoke as NATO ships began patrolling off Libya's coast and as airstrikes, missiles and energized rebels forced Moammar Gadhafi's tanks to roll back from two key western cities.
Despite disorganization among the rebels -- and confusion over who ultimately would run the international operation -- coalition airstrikes and missiles seemed to thwart Gadhafi's efforts to rout his opponents, at least for now.
Coalition aircraft hit a fuel depot in Tripoli, a senior government official told reporters in a late-night news conference. Deputy Foreign Minister Khaled Kaim at first denied reports that Gadhafi's compound in Tripoli had been hit, then backtracked and said he had no information about that. Other targets Wednesday were near Benghazi and Misrata, he said.
The Obama administration, meanwhile, turned up the pressure on quarreling NATO allies to take command of the air war, suggesting the United States could step away from its leadership role as soon as this weekend, even with the conflict's outcome in doubt.
In Congress, House Speaker John Boehner, R-Ohio, demanded that Obama quickly spell out the nation's precise goals in Libya. White House officials said Obama would keep updating the American people and a formal address was possible. Secretary of State Hillary Rodham Clinton said order could be resolved quickly -- if Gadhafi would just quit.
"Gadhafi has a decision to make," Clinton told reporters at the State Department. "And the people around him each have decisions to make. The quickest way for him to end this is to actually serve the Libyan people by leaving."
In an interview with the Spanish-language network Univision, Obama was asked whether a land invasion would be out of the question if air strikes failed to dislodge Gadhafi. "Absolutely" out of the question, Obama said.
Asked about the exit strategy, Obama didn't lay out a vision for ending the international action, but rather said: "The exit strategy will be executed this week in the sense that we will be pulling back from our much more active efforts to shape the environment. We'll still be in a support role, we'll still be providing jamming and intelligence and other assets that are unique to us, but this is an international effort that's designed to accomplish the goals that were set out in the Security Council resolution."
Gates said the allied mission in Libya was clear but the outcome was not. "I think there are any number of possible outcomes here, and no one is in a position to predict them," he said. Possibilities, he said, include more major defections from the inner circle around Gadhafi, who has ruled the North African nation for 42 years, and more divisions within his family.
Gates, himself an early skeptic of American military intervention in Libya, said Obama made clear from the start of the international air campaign Saturday that the United States would run it for only about a week. The assault began with a barrage of U.S. cruise missiles fired by ships and submarines in the Mediterranean and with American Stealth bomber flights -- the first war initiated by a president who inherited two others.
From Ajdabiya in the east to Misrata in the west, the coalition's targets included Libyan troops' mechanized forces, mobile surface-to-air missile sites and lines of communications that supply "their beans and their bullets," said Rear Adm. Gerard Hueber, a top U.S. officer in the campaign in Libya.
Gadhafi's air force, Hueber said, essentially has been defeated. He said no Libyan aircraft had attempted to fly over the previous 24 hours.
"Those aircraft have either been destroyed or rendered inoperable," Hueber told Pentagon reporters by phone from the Mediterranean Sea.
NATO warships, meanwhile, started patrolling Wednesday to enforce the U.N. arms embargo against Libya. Alliance spokeswoman Oana Lungescu said the action sought to "cut off the flow of arms and mercenaries," activity that intelligence reports say is continuing.
In a letter to the White House, Boehner said Obama still must provide a clear and robust assessment of the mission and how it will be achieved. Boehner did not call for a vote in the House on the commitment of U.S. military resources, as some lawmakers have demanded.
The U.S. military operations in Libya will cost hundreds of millions of dollars and force Congress to seek help next week for the cash-strapped Pentagon, which is operating on a short-term funding resolution.
Sen. Carl Levin, D-Mich., chairman of the Senate Armed Services Committee, said Wednesday that he had asked the Defense Department for an accurate estimate of the cost of the mission.