According to NBC, the U.S. has launched its first attack on Libyan forces. The attack comes minutes after French president Sarkozy announced that allied air forces have gone into action in Benghazi, Libya. Read more after the jump…

@ItsLukieBaby

(MSNBC)–French President Nicolas Sarkozy said allied air forces had gone into action on Saturday over Libya and were preventing Moammar Gadhafi’s forces from attacking the rebel city of Benghazi.

A French official said a French fighter jet had fired on a Libyan military vehicle, in a first reported strike in the international campaign to enforce a no-fly zone. Overall, at least four Libyan tanks were destroyed in French strikes, Al Jazeera reported.

American ships and aircraft stationed in and around the Mediterranean Sea did not participate in initial French air missions, but the U.S. was preparing to a launch a missile attack on Libyan air defenses, according to two U.S. officials familiar with the unfolding intervention.

One official said the U.S. intended to limit its involvement — at least in the initial stages — to helping protect French and other air missions by taking out Libyan air defenses.

An attack against those defenses with Navy sea-launched Tomahawk cruise missiles was planned for later Saturday, one official said. Both officials spoke on condition of anonymity because of the sensitivity of military operations.

The official said that depending on how Libyan forces responded to initial intervention by the French and others, the U.S. could launch additional attacks in support of allied forces. The intention was to leave it to other nations to patrol a no-fly zone over Libya once air defenses are silenced, the official said.

French Defense Ministry spokesman Thierry Burkhard said the allies’ initial attack was reported around 1645 GMT Saturday (12:45 pm ET).

He said no hostile fire on the French jet had been reported.

France sent a dozen Mirage and Rafale jets Saturday to survey the one-time opposition stronghold of Benghazi and the 150 kilometer-by-100 kilometer no-fly zone, Burkhard said.

“All aircraft that enter into this zone could be shot down,” he said.

The strike came less than two hours after top officials from the United States, Europe and the Arab world agreed in Paris to launch a risky military operation to protect civilians from attacks by Gadhafi’s forces.

It also came after Libyan government forces attacked Benghazi earlier Saturday, apparently ignoring a proclaimed cease-fire.

“Our planes are already preventing air attacks on the city,” Sarkozy said adding that military action could be halted if Gadhafi stopped his forces.

“Our determination is total,” the French leader said.

Asked if the aim of the military intervention was to overthrow Gadhafi, U.S. Secretary of State Hillary Clinton, in Paris for the meeting about Libya, did not answer the question directly but said the aim of Western powers was to protect civilians.

“If the international community is to have credibility … then action must take place,” Clinton told a news conference.

Clinton added that “we have every reason to fear that left unchecked, Gadhafi will commit unspeakable atrocities.”

Separately, President Barack Obama said the U.S. and its allies were prepared to act with urgency to end violence against civilians in Libya. “Our consensus was strong, and our resolve is clear. The people of Libya must be protected,” Obama said in Brazil, on the first day of a three-country Latin American tour.

The president was scheduled to make another statement on Libya within the hour, White House spokesman Jay Carney said.