Israel's prime minister has pledged to build a fortified fence along the frontier with Syria, warning that hardline Islamist forces have taken over the area.
Binyamin Netanyahu spoke at a weekly cabinet meeting on Sunday as Syrian President Bashar al-Assad delivered a rare nationwide address in Syria, calling for a national reconciliation conference.
Assad claimed that "terrorists who carry the ideology of al-Qaeda" were active in his country and demanded that foreign countries stop arming the rebels.
Netanyahu said the Syrian regime was "unstable", and Israel was concerned about the country's chemical weapons capabilities.
He said Israel needed a barrier on its frontier with Syria, similar to a structure it has almost completed along its border with Egypt - which has nearly stopped the flow of African migrants.
Israel has largely stayed out of the civil war that has engulfed Syria and left more than 60,000 people dead according to the UN, but it is concerned that violence could spill over.
Israel worries that Assad might try to draw it into the fighting as a distraction if his situation becomes desperate.
An even greater concern for Israel is a scenario in which Assad is toppled, Islamists take his place and gain control of Syria's stockpile of chemical weapons.
"We intend to erect an identical fence, with a few changes based on the actual territory, along the Golan Heights," Netanyahu said.
"We know that on the other side of our border with Syria today, the Syrian army has moved away, and in its place, global jihad forces have moved in."
"Global jihad" is the term Israel uses for forces influenced by al-Qaeda, and Syria's rebels include some al-Qaeda-allied groups.
"We are co-ordinating our intelligence and readiness with the United States and others so that we might be prepared for any scenario and possibility that could arise," Netanyahu said.
His office did not say how long it would take to complete the project.
Golan Heights tensions
Israel captured the Golan Heights in the 1967 Middle East war and later annexed the strategic plateau, a move not recognised by the international community.
Despite constant hostility between the two countries, Syria has kept the border mostly quiet since a second war in 1973.
Israel has grown jittery since pro-Palestinian activists breached the frontier during two demonstrations in 2011. Following that unrest, Israel began laying mines along the frontier and reinforcing the fence that already exists.
Defence officials say they have already fortified 10km out of the planned 70km route it plans along the edge of the occupied Golan Heights.
Since the uprising against Assad began in March 2011, several mortar rounds and other light munitions have landed on the Israeli side of the frontier.
Israel suspects these were cases of stray fire and were not intended to spark a new front, but Israel fired warning shots back to deter further incidents.
Israel has almost completed a barrier along 200km of its border with Egypt to block African migrants and fighters from crossing in from the lawless Sinai Peninsula.
Israel previously constructed a separation barrier along, and in, the West Bank.