Libya is no paradigm for a similar intervention to stop the deadly crackdown in Syria, senior Canadian and NATO officials said Saturday.

The Libya campaign "legitimized the authority of the broader community to act" to protect civilians under attack by the former regime of murdered leader Moamer Kadhafi, Canadian Defense Minister Peter MacKay told a panel discussion at the Halifax International Security Forum.

"But we have to proceed with caution in the application of this (new) norm... We should not charge in."

NATO partnered with Arab states earlier this year to stop Libyan strongman Moamer Kadhafi's assault on civilians in an ultimately failed bid to crush a revolt.

In Syria, "while there is obviously violence... we're not in a situation where the responsibility to protect applies," MacKay concluded, citing an international legal standard normally applied in cases of genocide.

"We have to be careful not to transplant everything that occurred in Libya... and superimpose it on Syria."

Lieutenant General Charles Bouchard, who was commander of the NATO military mission in Libya, said "Libya should not be a blueprint for the future."

"Syria is different: it's in the Middle East, it's got different neighbors and it has different regional support," he explained, alluding to concerns that war in Syria would draw Iran and others into a bloody conflict.

International pressure is mounting on Syrian President Bashar al-Assad's regime over its repression of demonstrations that erupted in Syria in mid-March, with the United Nations estimating over 3,500 people have been killed.

However, Russia has deeply opposed Western efforts to internationalize the crisis, fearing it could clear the way for a Libya-style military intervention under a UN mandate.

In October, Russia and China vetoed a Western-drafted UN Security Council resolution that would have threatened Assad's regime with "targeted measures" over its crackdown.

An Arab League deadline for Damascus to stop its lethal crackdown on protesters meanwhile expired a day after Syrian security forces killed at least 15 civilians, including two children.

Syria had been told by its Arab peers to stop the lethal repression against protesters by midnight local time on Saturday or risk sanctions, and the Arab League has already suspended it from the 22-member bloc.

Suat Kiniklioglu, former chair of the Turkish parliamentary committee on foreign affairs, also told the Halifax forum that Syria's main opposition group "needs political maturing, and must be more representative" of the Syrian people.

Syria is ruled by minority Alawites, an offshoot of Shiite Islam, while protesters demanding reforms are largely from its Sunni majority.