The Israeli army said it launched an operation dubbed "Northern Shield" to destroy "attack tunnels" it accused the Iran-backed Lebanese militia of digging under the border.
Israel has been using what it says is new technology to detect and destroy tunnels built by Hamas in the south, under the fence with Gaza. "I will discuss with Mike Pompeo a series of regional developments, as well as the steps we are taking together to block the aggression of Iran and its proxies in the north", Netanyahu told reporters before boarding. "Hamas uses the tunnels for tactical operations".
Education Minister Naftali Bennett also briefly threatened to resign and pull his party out of the coalition, toppling the government, if he were not given the defense portfolio, saying he would work to restore Israel's military strength.
Israel is also trying to send a message of deterrence to Hezbollah, he said, which as of Tuesday had not reacted to the news that Israel had uncovered one of its tunnels and plans to destroy more. A small explosion scared him away and the tunnel was later blown up with a more powerful blast.
A United Nations peacekeeping force which monitors the border region said it had increased patrols but noted the area remained calm.
Since the end of the 2006 war, Israeli forces have regularly violated Lebanon's sovereignty, with the regime's officials even threatening another offensive against the Arab country.
Conricus said Hezbollah has been hiding its efforts within the civilian infrastructure.
It said the army had boosted its presence and readiness and was prepared for "various scenarios".
Elsewhere in his comments, Hoballah stressed that Hezbollah fighters are capable of blocking any Israeli assault and launching counter-attacks on the enemy. Israel's border with Lebanon has been relatively quiet in the years since, but Israel has continued to identify the Shiite militant group and its expanding weapons cache of tens of thousands of rockets as a major threat.
Israel appears increasingly concerned that Iran is attempting to transfer some of its military influence from Syria, where Russian Federation is the government's top ally, to Lebanon.
Additional IDF troops were deployed to northern Israel as a precaution against potential attacks by Hezbollah, but no reservists were called up.
This picture taken on December 4, 2018, from the southern Lebanese village of Kfar Kila shows a view of Israeli machinery operating behind the border wall in Israel (R).
Neither side appears interested quite yet in another full-fledged confrontation like the 2006 war, but any skirmish could spark an all-out conflict along the tense border.