AMNA NAWAZ: Welcome to the "News Hour."

Heavy overnight fighting in Southern Lebanon between Israel and Hezbollah militants threatened today to derail the initial U.S.-Iran agreement to end the war.

But a last-ditch effort to secure another cease-fire succeeded, for now.

And the Americans and Iranians plan to meet soon to begin to hammer out a longer-term accord.

Our White House correspondent, Liz Landers, starts off our coverage again tonight.

LIZ LANDERS: From dusk until dawn, Israeli missiles rained down on more than 100 targets, rocking Southern Lebanon and clouding the horizon with smoke, more city blocks reduced to rubble.

Lebanese health officials reported nearly 50 people killed.

They did not say how many were militants.

The strikes appeared to be the last shots against Hezbollah before a commitment to calm.

A U.S.

official confirms to the "News Hour" that Israel and the Iran-backed militant group agreed to a conditional cease-fire facilitated by Qatar and the U.S.

But Israel says that it's keeping its forces inside Lebanon and, after reasserting its right to self-defense, appeared to hit Hezbollah after the cease-fire began.

BRIG.

GEN.

EFFIE DEFRIN, Israeli Defense Forces Spokesperson (through translator): We are maintaining a forward defensive presence as long as there's a threat.

As long as Hezbollah remains a threat, we will remain forward-positioned.

LIZ LANDERS: Israel says its latest strikes were to avenge four of its soldiers who they say were killed in a Hezbollah attack inside Lebanon.

Israel's ramped-up fighting in Lebanon and its rhetoric has threatened to unravel a new round of talks between the U.S.

and Iran.

Both Washington and Tehran reached an agreement to stop the war on -- quote - - "all fronts, including in Lebanon."

A war of words spilled out across social media earlier today.

Israel's hard-line national security minister, himself convicted of terror offenses in Israeli court, wrote -- quote -- "With all due respect to the Americans, the blood of our sons and the security of our citizens are not forfeit.

All of Lebanon must burn."

Iran's top diplomat replied, calling the Israeli government a -- quote -- "genocidal death cult" whose -- quote -- "only interest is permanent war."

Far from the battlefront to a placid lakeside in Switzerland, heavy security remains in place.

And mediators from Qatar wait at the lavish resort that's set to host the next round of peace talks between U.S.

and Iranian negotiators.

J.D.

VANCE, Vice President of the United States: All right, good morning, everybody.

LIZ LANDERS: Vice President J.D.

Vance delayed his trip for today's scheduled meeting near Lucerne, the White House citing logistics that have -- quote -- "never been simple or predictable."

No word on when the direct talks will begin.

That abrupt postponement comes just days after President Trump signed the preliminary deal to try and end the war.

DONALD TRUMP, President of the United States: It's 60 days, have to make a deal.

Otherwise, we will do things that won't make them happy, but I don't think it's going to get to that.

I think it's going to be very good.

LIZ LANDERS: The president showed little concern about the talks as he unveiled a new Air Force One Boeing 747 today, a refitted $400 million jet gifted to him by Qatar.

And in a new interview with Axios taped before last night's violence, Mr.

Trump defended that deal and said the fighting exacted total surrender from Iran.

QUESTION: And it certainly brought Iran to the table more than before.

However, beginning of the conflict, you had talked about you only wanted unconditional surrender.

And... DONALD TRUMP: Well... QUESTION: ... the MOU doesn't look like unconditional surrender.

DONALD TRUMP: Well, it really probably is unconditional surrender.

QUESTION: It is?

DONALD TRUMP: I think so.

LIZ LANDERS: Speaking on "The Today Show," former President Barack Obama criticized the conflict and lamented the U.S.

withdrawal from his own nuclear deal, the JCPOA, which President Trump scrapped in his first term.

BARACK OBAMA, Former President of the United States: We have now fought a war, spent billions and billions of dollars, put an enormous strain on our military.

A lot of people have died.

And it feels like we're back where we were before we started the war, except maybe a little bit worse.

LIZ LANDERS: As for the state of the talks, Iran's Foreign Ministry says plans are still under way to host a meeting with the U.S.

in the coming days.

But that's only if fighting does not return to Lebanon.

For the "PBS News Hour," I'm Liz Landers.