Israel is to build a steel fence between the Golan Heights and Syria amid fears that its neighbour's civil war could spill over or create an exodus of refugees.
The pledge from Prime Minister Benjamin Netanyahu came days after the Defence Ministry announced the near-completion of a 240-kilometre fence along the southern border with Egypt.
"We intend to erect an identical fence, with a few changes based on the actual territory, along the Golan Heights," Netanyahu said. "We will defend this border against infiltration and terrorism, just as we are doing on the [southern] border."
Israeli military sources warned in November that opposition forces had taken control of villages and territory near the United Nations-monitored buffer zone between Syria and the Israeli-occupied Golan Heights.
Several shells fired by regime forces have landed on the Golan. Israel has also said it will take military action if necessary to prevent Syria's chemical weapons falling into the hands of what it terms "global jihadists" in Syria or Hezbollah in Lebanon.
The Syrian regime was "very unstable", Netanyahu said. "The question of chemical weapons here worries us and … we are coordinating our intelligence and readiness with the United States and others so that we might be prepared for any scenario."
Netanyahu's office has declined to comment on reports that he made a secret visit to King Abdullah of Jordan to discuss the risk of chemical weapons being obtained by militants. Israel has effectively annexed the Golan Heights, a move not recognised by the international community.