Top U.S. General says stopping a Syrian chemical attack is 'almost unachievable'

General Martin Dempsey says the U.S. must instead rely on deterrence

America rules out sending in ground troops under hostile circumstances

But may provide some forces if President Assad agrees to peaceful end

There are fears Assad may use sarin and mustard gas in bid to save regime



Stopping a chemical attack by the Syrian government would be nearly impossible so opposing forces will need to rely on deterrence, a top U.S. general has said.



The United States has largely ruled out sending in ground troops to secure Syrian chemical weapons under hostile circumstances, but the Pentagon could provide some forces if the Assad regime ever agrees to a peaceful transition.

General Martin Dempsey, chairman of the Joint Chiefs of Staff, said the U.S. must instead continue to warn Syria that using such weapons would be unacceptable.

Ruled out ground invasion: U.S. General Martin Dempsey (pictured, right, with Defense Secretary Leon Panetta) explains why it would be nearly impossible to prevent a chemical attack by President Assad's forces

Hoping for peaceful transition: Secretary of Defense Leon Panetta (left) says his biggest concern is how the U.S. and allies would secure the chemical and biological weapons sites scattered across Syria

'The act of preventing the use of chemical weapons would be almost unachievable,' Dempsey said during a Pentagon press conference.



'You would have to have such clarity of intelligence, you know, persistent surveillance, you'd have to actually see it before it happened, and that's - that's unlikely, to be sure.'

Speaking to Pentagon reporters, Defense Secretary Leon Panetta says his biggest concern is how the U.S. and allies would secure the chemical and biological weapons sites scattered across Syria and ensure the components don't end up in the wrong hands if the regime falls, particularly under violent conditions.



He said the U.S. is preparing no options for having U.S. ground troops in that country if the regime falls while under attack.

Obstacle to peace: There are worries that if Syrian President Bashar Assad (pictured) is toppled, Islamic extremists could gain control of Syria's stockpile of chemical weapons

Could get worse: Smoke billows over destroyed buildings in Aleppo in October. There are fears that Assad might use his chemical weapons, perhaps on his own people, in a last-ditch effort to save his regime

But he added: 'You always have to keep the possibility that, if there is a peaceful transition and international organizations get involved, that they might ask for assistance in that situation.'

There are widespread worries among allies and countries in the region that if Syrian President Bashar Assad is toppled, Islamic extremists could gain control of Syria's stockpile of chemical weapons, which includes sarin and mustard gas.



And there are lingering worries that Assad might use his chemical weapons, perhaps on his own people, in a last-ditch effort to save his regime.

President Barack Obama has said the regime's use of chemical weapons against the rebels would be a 'red line' and change his 'calculus' about possible military intervention there.

Fears escalated early last month when U.S. officials said there was evidence that Syrian forces had begun preparing sarin, a nerve agent, for possible use in bombs.



Displaced: A Syrian refugee carries a new tent at the Al-Zaatari refugee camp in the Jordanian city of Mafraq on Thursday. At least 60,000 people have died during Assad's two-year crackdown, according to the U.N.

But Panetta later said that it appeared the Syrian government had slowed its preparations for the possible use of the weapons.

The Pentagon has put together a variety of options for securing the weapons under a range of circumstances, Dempsey said.



And he acknowledged the U.S. has been in contact with NATO allies, such as the Czech Republic, who have developed capabilities for handling chemical, biological and nuclear weapons.



But Dempsey said not specific request has been made of the Czech Republic.

At least 60,000 people have died during Assad's two-year crackdown on rebels, according to a recent U.N. estimate.



Opposition fighters have seized large swaths of territory in northern Syria, and on Thursday activists said they now control parts of a strategic air base.



But despite significant rebel advances on the battlefield, the opposition remains outgunned by government forces and has been unable to break a stalemate on the ground.