Israel shot down a Syrian drone that penetrated its airspace on Wednesday, Prime Minister Benjamin Netanyahu said, highlighting an escalation of volatility near the frontier that Netanyahu discussed in Moscow with Damascus's biggest ally.

"A drone penetrated from Syria's territory to Israel's territory several hours ago. It was successfully shot down. And I would like to point out that we will be preventing any attempts to violate our air or land border," Netanyahu said on Wednesday as he met President Vladimir Putin.

It was the second time in less than three weeks Israel says it fired a Patriot missile at a drone that flew across the frontier. Tension has increased at the border as President Bashar Assad's forces have pressed toward it with an assault against rebels.