OTTAWA -- Foreign Affairs Minister John Baird expressed "deep and grave" concern Tuesday about the possibility of a chemical weapons attack in Syria, just as the Pentagon chief said the threat of one might be diminishing.

The most recent assessment by U.S. Defence Secretary Leon Panetta clashed with Baird's description of the possible consequences of a chemical attack against innocent Syrian civilians or "neighbours" -- Syria's enemy, Israel.

Moreover, the two, specialized Canadian Forces response teams that reportedly could be called to respond to a chemical weapons attack in Syria have yet to receive their warning orders to deploy, The Canadian Press has learned.

Neither the Disaster Assistance Response Team (DART) nor the Canadian Joint Incident Response Unit -- which handles chemical, biological and nuclear incidents -- have been put on notice to move, said multiple senior defence sources.

Baird said the threat of a chemical weapons attack would be "top of mind" at the big international meeting in Morocco this week involving more than 110 countries and the Syrian opposition.

"There is considerable concern that some recent actions by the Syrian regime have indicated that they were beginning to mobilize, to be in a position where they could use them," Baird said from Morocco.

"That has sparked increased deep and grave concern."

In contrast, Panetta said Tuesday that, "the intelligence has really kind of levelled off" about Syria's most recent chemical weapons movements.

"We haven't seen anything new indicating any aggressive steps to move forward in that way," he said.

Those remarks dovetail with the fact the Forces have yet to send out what is called a warning order to high-readiness units, such as DART, to be ready to deploy within 48 hours.

Such an order comes when action is imminent, but no such instruction has been given, sources said.

Since June, when a United Nations peace effort stalled, military planners have been spinning different scenarios for a potential Canadian contribution to a possible international military intervention for Syria.

The possibility that Syrian President Bashar Assad might use chemical weapons against his own people sparked recent warnings of serious consequences from the Obama administration and its allies. Assad's bloody crackdown on the 20-month-old popular uprising -- now a civil war -- has cost the lives of an estimated 40,000 people.

The Assad regime is widely believed to be harbouring a large arsenal of chemical weapons, including sarin and mustard gas.

"We are, like others, keeping an eye on the entire crisis that's playing out in Syria, as best as we can. We're in a period of seeking to anticipate which way this could go," Lt.-Gen. Stuart Beare, Canada's overseas commander, told The Canadian Press in a recent interview.

"Let's just say, we're watching it and if we're required to offer military advice, certainly the chief (of defence staff) would do that, and if we're required to be prepared to provide military responses, I obviously cannot speculate on those; we'd obvious be prepared to do that,"

The Forces also examined options ranging from humanitarian assistance to the establishment of safe havens for refugees up to the enforcement of a no-fly zone. Canada was one of eight NATO countries to send fighter jets to support the UN-sanctioned no-fly zone over Libya last year that helped topple dictator Moammar Gadhafi.

All of it was designed to give cabinet a choice should NATO or the UN call for assistance.

The possible proliferation of chemical weapons has been a subject of more high-level, regional debate.

"It's impossible to predict which way this thing is going to go," Beare said.

Baird laid out three scenarios for how chemical weapons might be used.

"We have been concerned for a good number of months that at a certain point in this conflict the weapons could be used against the Syrian people or be used against the neighbours of Syria," he said.

"Or worse yet, they could fall into the wrong hands, of an extremist radical group."

Baird wouldn't say whether Canada had any plans to follow the U.S. in designating one of the Syrian rebel groups a terrorist organization. Earlier this week, the U.S. State Department slapped that label on Jabhat al-Nusra, saying the anti-Assad militia group was linked to al-Qaida.

"We are concerned about a small element in Syria that is particularly radicalized and extremist with connections to known international terrorist organizations. This causes us grave concern."

Baird said the Morocco meeting would "look at what international pressure we can bring to bear to try to encourage peace in Syria and encourage Assad to step down and go."

Panetta suggested Assad might be taking the West's warnings seriously about not using chemical weapons.

"I like to believe he's got the message. We've made it pretty clear. Others have as well," he said.

But Panetta made clear that no one can predict the regime's next moves.

"Our concern is that if they feel like the regime is threatened with collapse, they might resort to these kinds of weapons."