WASHINGTON — President Barack Obama today categorically ruled out a land invasion to oust Libyan leader Moammar Gadhafi as coalition forces launched a fifth day of air strikes against government military targets in the North African nation.

He said the United States this week will pull back from its dominant role in the international campaign aimed at preventing Gadhafi from attacking civilians.

In attacks early today, missiles from F-15 fighter jets destroyed Gadhafi missile sites around Tripoli. In two cities where pro-Gadhafi troops have besieged civilians, the international force struck a government ammunition depot outside Misrata and other planes hit ground forces outside Ajdabiya.

Obama was asked in an interview with the Spanish-language network Univision if a land invasion would be out of the question in the event air strikes fail to dislodge Gadhafi from power. Obama replied “absolutely.”

Asked what the exit strategy is, he didn’t lay out a vision for ending the 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.”