The Israeli military said on Wednesday it was calling up two reserve brigades to the north, where its forces are involved in cross-border clashes with the Lebanese group Hezbollah.

"The IDF (military) is calling up two reserve brigades for operational missions in the northern arena," the military said in a statement, adding that this would "enable the continuation of combat against the Hezbollah terrorist organization".

Parliament Speaker Nabih Berri revealed to Asharq al-Awsat newspaper on Wednesday that he is carrying out “serious efforts” with international parties, including the U.S., to halt the ongoing Israeli escalation against Lebanon.

After almost a year of trading fire, Israel and the Lebanese Hezbollah are now engaged in ferocious confrontations that threaten to turn into a full-blown war.

Israel faces a much more formidable foe in Hezbollah than it faced in Hamas in the Gaza Strip. Many consider the Iran-backed group the strongest paramilitary force in the region — but the group also has political and social wings with considerable power in Lebanon.

The White House said Wednesday that a missile launched by Hezbollah in Lebanon at Tel Aviv in Israel was "deeply concerning," but that a diplomatic offramp remains to avoid "all-out war."

"It's certainly deeply concerning, obviously to the Israelis, of course, but also to us," White House National Security Council spokesman John Kirby told CNN. "There is still time and space for a diplomatic solution here to de-escalate the tensions and to prevent an all-out war."

By Mireille Rebeiz, Dickinson College

Lebanese families have been fleeing the country's south in the thousands amid escalating tensions and an Israeli bombardment that has so far killed hundreds.

It has been a devastating week for Hezbollah and the people of Lebanon.

Bombs hidden in the group's pagers and walkie-talkies killed dozens of people and wounded thousands — many of them Hezbollah members. Israeli strikes on Beirut killed two of Hezbollah's top commanders. And Israel has bombed what it said were 1,600 militant sites across large parts of Lebanon, killing hundreds of people and displacing thousands.

Fadi, a type of rocket used for the first time by Hezbollah against Israel, has more explosive power and range than rockets deployed previously, but lacks precision, experts say.

Some hawkish Israeli generals think that Hezbollah can be forced to back down, current and former Israeli officials told The New York Times, while others in the government think Israel must reach a deal with Hamas before expanding the war.

Hezbollah said Tuesday that it targeted a military base in north Israel near Safed twice with salvos of rockets, as Israel pounded Lebanon with air strikes, saying it was targeting the Iran-backed group.

"In defense of Lebanon and its people", Hezbollah targeted "the Dado base" near north Israel's Safed -- the headquarters of the Israeli military's northern command -- with a total of 90 rockets, the Iran-backed group said in two separate statements.

Israel is not eager for a ground invasion of Lebanon, the country's ambassador to the U.N. Danny Danon said, as Israel carried out deadly strikes on its northern neighbor.

"We had experience in Lebanon in the past. We are not eager to start any ground invasion anywhere," Danon said Tuesday as intensified Israeli strikes stoked fears of a wider war in the Middle East.