Last Updated 7:51 a.m. ET
BRUSSELS - The Libyan government closed its airspace Friday to all traffic, reacting to a U.N. resolution authorizing the use of force and a no-fly zone to protect the Libyan people from attacks by forces loyal to strongman Muammar Qaddafi.
Europe's air traffic control agency, Eurocontrol, told airlines on Friday that "the latest information from Malta indicates that Tripoli (air control center) does not accept traffic."
The Brussels-based agency's map of air traffic over Europe and the Mediterranean showed that Libyan airspace was off-limits.
Meanwhile, Britain, France and NATO were holding emergency meetings Friday after the United Nations Security Council authorized "all necessary measures" to stop attacks on civilians in Libya including strikes by sea and air.
Prime Minister David Cameron said Friday that Britain will send Typhoon and Tornado fighter jets "in the coming hours" to help enforce a no-fly zone over Libya. Cameron said Britain, France and Arab nations are to meet Saturday in Paris on no-fly zone.
As of Friday morning the U.S. had yet to announce what its role in the no-fly zone would be.
The U.S. has positioned a host of forces and ships in the region, including submarines and destroyers and amphibious assault and landing ships with some 400 Marines aboard. It also could provide a range of surveillance assets, CBS News national security correspondent David Martin reports from the Pentagon.
Martin told CBS' "The Early Show" that a no-fly zone would begin with air strikes against Qaddafi's air defense network - likely by American cruise missiles - so that planes patrolling Libya cannot be shot down by surface-to-air missiles.
"This may sound like just a lazy patrol over Libyan territory, but it begins violently," said Martin.
That would clear the way for air raids against Qaddafi's army, which is rapidly closing in on the last rebel stronghold in Benghazi.
Reporting from Tripoli, CBS News correspondent Mark Phillips reporting from Tripoli, says announcement of the U.N. resolution promoting very different responses in two Libyan cities.
In Benghazi, celebrations and fireworks greeted the U.N. vote. The rebel cause had all but lost hope of being able to resist the Qaddafi forces mounted against them. Now with foreign help, they have hope, and just in time.
The mood was defiant in Tripoli, where a crowd of regime supporters interrupted a government news conference.
Forces loyal to the Qaddafi regime have been mounting for a final assault. While the rebels have been unable to resist the heavy weaponry at the government's disposal, Qaddafi's troops are now effectively in the crosshairs of NATO air power; the regime faces a choice.
The choice facing Qaddafi's forces is to move forward toward Benghazi, in which case they obviously become targets for potential NATO air strikes; or, to hold their position, in which case the choice becomes more of a problem for NATO.
The reaction from the regime here, particularly from Colonel Qaddafi himself, was very telling. He told a Portuguese interviewer, "This is madness. If this world is crazy, we will be crazy, too."
Eurocontrol said Friday it had no information on how long Libya's airspace would be closed, but the agency said it had halted all air traffic to Libya for 24 hours.
"We applied a zero traffic rate for the whole day," said a Eurocontrol official who spoke on condition of anonymity because she was not authorized to speak to the news media.
She said the closure could also be affected by decisions made Friday by NATO, the North Atlantic military alliance.
"The international community has come together in deploring the actions of the Qaddafi regime and demand that the regime stop its actions against the Libyan people," British Ambassador Mark Lyall Grant said after the resolution was approved by a vote of 10-0 with five nations abstaining, including veto-holders Russia and China and non-permanent members Brazil and India.
CBS News Foreign Affairs Analyst Pamela Falk reports it is now up to Qaddafi if the action turns into an air war, because by authorizing the use of force and imposing crippling economic sanctions, the U.N.'s resolution has teeth.
"The future of Libya should be decided by the people of Libya," U.S. Ambassador Susan Rice told the Security Council. "The United States stands with the people of Libya in support of their universal rights."