A barrage of U.S.-led airstrikes opened the door for Libyan rebels to retake the eastern city of Ajdabiya Saturday, handing President Obama a tangible example of progress as he defends the military action to war-weary Americans.
The administration has been under pressure to better explain why the United States was embroiling itself in another Muslim conflict and to clarify what America's continuing role will be as it begins to turn control of the week-old operation over to NATO.
Obama cited "significant success" in the war Saturday, and he and others defended the U.S. intervention as lawful and critical to save thousands of lives and stabilize a strategically vital region in the Middle East.
"The United States should not and cannot intervene every time there's a crisis somewhere in the world," Obama said in his weekly radio and Internet address Saturday. But with Libyan leader Moammar Gadhafi threatening "a bloodbath that could destabilize an entire region it's in our national interest to act. And it's our responsibility. This is one of those times."
The Pentagon said U.S.-led forces pounded Libyan ground troops and other targets along the Mediterranean coast and in Tripoli, and the contested cities of Misrata and Ajdabiya in strikes overnight, but they provided no details on what was hit. A Pentagon spokesman, Navy Capt. Darryn James, says there were no Tomahawk cruise missile strikes overnight.
All together, the Pentagon said the U.S. military launched nearly 100 strikes overnight, just slightly higher than a day ago.
"Every day, the pressure on Gadhafi and his regime is increasing," Obama said in the Saturday address, which aired just after Libyan rebels retook Ajdabiya, celebrating in the streets.
But the rebels remain a long way from being in a position to approach Tripoli.
To reach the capital, they will have to traverse hundreds of miles of sparsely populated desert highway that runs through some staunchly loyalist areas, notably Gadhafi's heavily guarded hometown of Sirte. On their last push west they reached Bin Jawwad, 37 miles beyond Ras Lanuf, before they were forced back by government soldiers. Bin Jawwad is more than 300 miles east of the capital, Tripoli.
Meanwhile, Defense Secretary Robert M. Gates rejected claims by Gadhafi's regime that innocent Libyans were killed in U.S. airstrikes, saying "the truth of the matter is we have trouble coming up with proof of any civilian casualties that we have been responsible for."
In an interview pre-taped for CBS News' "Face The Nation," Gates said there were numerous intelligence reports suggesting the regime was taking bodies of people killed by pro-government forces and placing them at sites attacked by U.S. planes.
Obama, who will speak to the nation Monday evening, has been roundly criticized by lawmakers for not seeking more congressional input on the war.
The Washington Post contributed to this report.