Speaking in Jerusalem before a meeting with the United Nations Security Council, Netanyahu called on Lebanon to reject the group and its clandestine efforts to breach the Israeli border.
"Their goal has been to penetrate our territory, to kidnap our people, including civilians, murder civilians and conquer the northern piece of the Galilee," Netanyahu said. "This is not merely an act of aggression; it's an act of war."
Israeli officials have said recent operations have uncovered four Hezbollah tunnels that cross from Lebanon, beneath the West Bank, into Israel. The latest was found last weekend, and stretched from the southern Lebanese village of Ramieh to the Israeli community of Zarit.
"Act in your defense and roll [Hezbollah] back, fight Hezbollah for the future of Lebanon," Netanyahu said Wednesday. "[The Lebanese army] certainly doesn't challenge [the tunnels]. They failed to take action to control their own territory, they failed to take action to prevent the use of their territory against a neighboring state, and they failed to dislodge the tyrannical Islamists. They haven't even tried."
Lebanon has complained that Israel regularly violates airspace, dating back to the end of the 2006 war between Israel and Hezbollah.