Canadian jets will "very soon" be a part of extensive aerial operations over Libya to protect innocent civilians, Prime Minister Stephen Harper says.

Harper's comment Saturday in Paris came as U.S. launched cruise missiles at Libyan targets as part of a co-ordinated international military intervention against a violent crackdown by forces loyal to Libyan ruler Moammar Gadhafi.

The prime minister was also quick to stress there are no guarantees that civilians or Canadian military personnel can avoid getting hurt in the mission.

"These campaigns are complicated and one cannot promise perfection," he told reporters following an emergency summit with representatives from the United States, as well as European and Arab nations.

"One cannot promise there will not be casualties on our side either. But obviously all precautions will be taken to minimize our own casualties and minimize those of innocent civilians.

"We should not kid ourselves. Whenever we engage in military action — essentially acts of war — these are difficult situations."

Harper reiterated the UN mandate does not call for ground troops and said he believes the international aerial and naval operations will put the squeeze on the longtime Libyan ruler's authority.

"If Mr. Gadhafi loses his capacity to enforce his will through vastly superior armament, that he simply won't be able to sustain grip on the country," Harper said. "He will not last very long."

Earlier Saturday, the Prime Minister's Office said Canada's six CF-18s deployed to the region need more time to get ready for any international military air mission to enforce a United Nations no-fly zone over Libya.

French President Nicolas Sarkozy, left, welcomes Canadian Prime Minister Stephen Harper before a crisis summit on Libya at the Elysee palace in Paris, Saturday. Christophe Ena/Associated Press "Canadian fighter jets have just reached the region and will require two days to prepare for any missions," Andrew MacDougall, the prime minister's press secretary, said in an email statement on Saturday.

The CF-18s have been deployed to join an international effort to enforce a UN Security Council resolution that is trying to prevent violence by forces loyal to Gadhafi against rebels and civilians.

Gadhafi announced a ceasefire Friday and invited international monitors to provide verification, but reports emerged Saturday of intensified fighting and airstrikes in the rebel stronghold of Benghazi.

But Harper on Saturday called Gadhafi's pledge "an obvious lie from the beginning."

Canada 'open to all options': Cannon

Canada's military effort was also acknowledged several times in remarks about Libya by U.S. Secretary of State Hillary Clinton on Saturday.

Clinton, who was at the emergency summit in Paris, repeatedly referred to the involvement of "our European and Canadian allies."

Harper was accompanied at the one-day summit by Foreign Affairs Minister Lawrence Cannon and Gen. Walt Natynczyk, the chief of the defence staff.

In an interview Saturday on CBC Radio's The House, Cannon said Canada is "open to all options" in responding to the Libyan crisis.

When asked by host Kathleen Petty if that includes "boots on the ground," Cannon said if that were required to "protect citizens that are being literally murdered by [Libyan leader Moammar] Gadhafi, that's what the resolution calls for."

With files from James Cudmore, Terry Milewski and The Associated Press