JERUSALEM, Dec. 4 (Xinhua) -- Israeli Prime Minister Benjamin Netanyahu vowed on Tuesday that Israel will act against those who try to harm it.

He made the remarks hours after the army launched an operation to destroy cross-border tunnels dug by the militia of Hezbollah.

"Whoever tries to attack the State of Israel will pay a heavy price," said a statement released by his office in the first remark on the "Northern Shield" operation, which started overnight between Monday and Tuesday.

"We are taking determined and responsible actions in all sectors simultaneously. We will continue with additional actions, open and covert, in order to ensure the security of Israel," he said.

Earlier in the morning, the military said it had launched the "Northern Shield" operation to "expose and thwart" attack tunnels that cross from southern Lebanon into northern Israel and were constructed by the Lebanon-based group of Hezbollah.

On Monday evening, Netanyahu held "a diplomatic-security meeting" with U.S. Secretary of State Mike Pompeo in Brussels, the prime minister's office said.

The prime minister updated the U.S. official on the expected operation, stressing that "Iranian aggression had to be thwarted in Syria, Iraq, Lebanon and elsewhere," according to the office.

Netanyahu also told Pompeo that the tunnels are "a gross violation of Israeli sovereignty and of UN Security Resolution 1701," a resolution from 2006 that calls for "cessation of hostilities in Lebanon."

Several hours after the operation began, the military released a photograph of a tunnel uncovered in the village of Kafr Kila in southern Lebanon. The army said the tunnel crossed the border and reached the northern town of Metula in Israel.

Israel and Hezbollah, an Iran-backed militia in southern Lebanon, had a month-long war in 2006 that ended in a cease-fire.