U.S. Secretary of State Antony Blinken has noted "growing concern over rising tensions" on the Lebanese-Israeli border in a telephone call with caretaker Prime Minister Najib Mikati, a statement said.

Blinken, however, "underscored continued U.S. support" for Lebanon's army, security forces and people, spokesperson Matthew Miller said in the Saturday statement.

Hezbollah deputy chief Sheikh Naim Qassem has vowed that Israel will pay a high price whenever it starts a ground offensive in the Gaza Strip, saying that his Lebanon-based group already is "in the heart of the battle."

The comments by Qassem came as Israel shelled and made drone strikes in southern Lebanon and Hezbollah fired rockets and missiles toward Israel. Hezbollah said six of its fighters were killed Saturday, the highest daily toll since the violence began two weeks ago.

By Asher Kaufman, University of Notre Dame

Lebanon, which is teetering on the edge of economic and political collapse, risks becoming entangled in the escalating war between Israel and Hamas.

Israeli Defense Minister Yoav Gallant said Saturday that Hezbollah "has decided to participate in the fighting" that is raging between Israel and the Gaza-based Hamas movement.

“Hezbollah has decided to participate in the fighting, and we are exacting a heavy price for this,” said Gallant during a visit to the border with Lebanon, referring to the deadly cross-border exchanges with the Iran-backed group that have been ongoing since the day that followed Hamas' Oct. 7 massive attack on Israel.

U.S. officials acted after they learned that the Israeli defense minister and other military officials supported a pre-emptive strike on Hezbollah, the New York Times has reported.

Biden met with Netanyahu and his war cabinet on Wednesday.

One Israeli soldier was killed Friday in clashes with Hezbollah on Lebanon's border, Israeli radio said, as the Israeli army announced it hit Hezbollah targets with airstrikes after rocket and anti-tank missile fire.

Israel on Friday ordered the 25,000 residents of the northern town of Kiryat Shmona to evacuate.

French President Emmanuel Macron said France had been in direct contact with Lebanon's Iran-backed Hezbollah to avoid a flare-up on Lebanon's southern border with Israel amid the ongoing war in Gaza.

"We sent messages to Hezbollah very directly through our ambassador and our services," Macron told a group of reporters, adding that despite rocket fire on the border there has been "no escalation" but "we remain very cautious."

Soldiers are everywhere and the last residents are hurriedly packing in the northern town of Kiryat Shmona where Israel fears Lebanon's Hezbollah could open up a second front in its war with Hamas.

As smoke rises from the nearby wooded hills following the latest cross-border exchanges, soldiers in fatigues can be seen eating sandwiches on cafe terraces, buying bandages in pharmacies or emerging in groups from the bus station.

More than 4,200 people have been displaced from villages in south Lebanon by clashes on the border with Israel, and local officials said Friday that they are ill-prepared for the much larger exodus that would ensue if the limited conflict escalates to an all-out war.

Some 1,500 of the displaced are staying in three schools in the coastal city of Tyre, about 20 kilometers (12 miles) north of the border.

Lebanon's national carrier Friday said it was cutting more than half of its flights as tensions along the border with Israel prompted more Western countries to warn against travel to Lebanon.