Israeli Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak on Sunday stressed that Israel was monitoring the spiraling civil war in Syria and was prepared to react if the regime's chemical or biological weapons reached either rebel forces' or Lebanese Hezbollah hands.

"We're closely following what is transpiring there, and are ready for any possible development," Netanyahu said at the opening of the weekly cabinet session, according to a Prime Minister's Office statement sent to Xinhua.

Barak, on a visit with new recruits at an induction center near Tel Aviv, said the army was watching for any sign that the regime of Syrian President Bashar Assad was preparing to either use, or transfer stocks of what is believed to be among the Middle East's largest stores of weapons of mass destruction, including sarin nerve gas, cyanide and blister agents like mustard gas.

Military officials said at the end of last week, that any sign that the weapons were moved out of Syrian government control would constitute a "causus belli" - an act of war to which Israel would likely respond.

On Friday, Barak told Israel's Channel 10 television, that "I have instructed the military to increase its intelligence preparations and prepare what is needed so that we will be able to consider carrying out an operation."