GEOFF BENNETT: Welcome to the "News Hour."

It is a tense night in Lebanon and Northern Israel after the second day in a row of major Israeli airstrikes.

Israel said it killed a senior Hezbollah commander in Beirut, while the militant group launched missiles at Israeli military and civilian sites.

The U.S. is trying to de-escalate, including in meetings at the United Nations General Assembly, where President Biden spoke today.

Nick Schifrin has more.

NICK SCHIFRIN: In Beirut today, the sound of sirens after an Israeli airstrike hit a residential building, leaving debris in the street, damaged cars, and Lebanese authorities said six dead and 15 wounded.

Israel said the target was a senior Hezbollah commander.

Down the coast, Lebanese stood in what used to be their homes after bombings crushed the village of Aaqbiyeh.

To the east, in the Beqaa Valley, residential buildings turned to rubble.

And in Southern Lebanon, the strikes continue.

Israel says its targets are hidden Hezbollah weapons.

But this week's victims include children like Misaab Al-Malla, and his mother, Aziza Ali Obeid.

AZIZA ALI OBEID, Southern Lebanon Resident (through translator): My children and I were at home, working and relying on God for support, when the Israeli enemy hit us.

They are just children.

NICK SCHIFRIN: The strikes have caused tens of thousands to flee their homes to cities that can't cope.

MUSTAFA HIJAZI, Sidon Crisis Management Unit (through translator): No doubt that the circumstances we are facing today are extraordinary with the aggression we are witnessing.

NICK SCHIFRIN: But Hezbollah continues its own aggression, including on this Israeli highway.

Hezbollah has fired thousands of rockets into Israel, today hitting this supermarket in the Arab-Israeli city of Tamra.

MOUSA ABU RUMI, Mayor of Tamra, Israel (through translator): Luckily, there were no physical injuries, but there have been victims of trauma in the city.

NICK SCHIFRIN: Hezbollah is part of Lebanon's government and offers social services, but, today, Israeli Prime Minister Benjamin Netanyahu said Hezbollah and its leader must be removed.

BENJAMIN NETANYAHU, Israeli Prime Minister (through translator): Nasrallah is leading you to the brink of the abyss.

He is endangering your country.

Rid yourselves from the grip of Hezbollah.

NICK SCHIFRIN: Seven thousand miles away, President Biden again called for de-escalation.

JOE BIDEN, President of the United States: Full-scale war is not anyone's interest.

Even as the situation is escalating, a diplomatic solution is still possible.

NICK SCHIFRIN: U.S. officials are trying to use the U.N. General Assembly to prevent all-out war, but a senior State Department official argues airstrikes designed to push Hezbollah to negotiate will lead to escalation.

JOE BIDEN: Today is the fourth time I have had the great honor of speaking to this assembly as president of the United States.

It will be my last.

NICK SCHIFRIN: Today was President Biden's un swan song, his final speech to the international community, after a half-century-career often focused on foreign affairs, with a world view defined by international collaboration and a hope that served as today's bookends.

JOE BIDEN: I entered public life not out of despair, but out of optimism.

Things can get better.

We should never forget that.

NICK SCHIFRIN: Biden acknowledged the wars that shadow this year's assembly, Gaza.

JOE BIDEN: Bring the hostages home, ensure security for Israel and Gaza free of Hamas' grip, ease the suffering in Gaza and end the war.

NICK SCHIFRIN: Sudan.

JOE BIDEN: The world needs to stop arming the generals and speak with one voice and tell them, stop tearing your country apart, stop blocking aid to the Sudanese people, end this war now.

NICK SCHIFRIN: And, as Volodymyr Zelenskyy listened and Russia's U.N. ambassador texted, Ukraine.

JOE BIDEN: We will not let up on our support for Ukraine, not until Ukraine wins a just and endurable peace on the U.N. Charter.

(APPLAUSE) NICK SCHIFRIN: But despite no near-term solutions to any of those wars, Biden's final message: Change can come.

JOE BIDEN: Some things are more important than staying in power.

's your people.

(APPLAUSE) JOE BIDEN: Every age faces its challenges.

I saw it as a young man.

I see it today.

But we are stronger than we think.

We are stronger together than alone.

What people call impossible is just an illusion.

NICK SCHIFRIN: But the fact is, U.S. influence to end the war in Sudan appears to be limited, Ukraine is struggling to hold the line, and Israel has so far resisted U.S. efforts for a cease-fire on Gaza or to avoid escalation in Lebanon.

So, as President Biden finished his final address to the international community, Secretary-General Antonio Guterres here had a much more sober look at the world.

He said -- quote -- "Our world is heading off the rails."

GEOFF BENNETT: Well, Nick, tell us more about how the U.S. is trying to de-escalate tensions between Israel and Lebanon.

NICK SCHIFRIN: U.S. officials, Geoff, are tight-lipped about exactly what they're doing.

But they say they have -- quote -- "concrete steps" they're discussing with allies and partners.

And the diplomatic deal that is on the table remains, a deal that would move Hezbollah back as demanded by Security Council Resolution 1701, back about six miles from the Israel-Lebanon border behind the Litani River.

That's the diplomatic deal that exists still on the table.

And Israel wants Hezbollah to delink its attacks on Israel from the war in Gaza.

Hassan Nasrallah, the secretary-general of Hezbollah, has been clear that their attacks will continue so long as the war in Gaza continues.

U.S. officials I speak to say that Hezbollah has taken a military hit over the last week, but they don't quite understand how that translates into the strategic gain that Israel is hoping for, returning 60,000 residents to their homes in Northern Israel.

And last week's attacks on Hezbollah pagers really hit Hezbollah where they are most vulnerable.

Geoff, and that means that Hezbollah is much more likely to escalate than choose diplomacy.

GEOFF BENNETT: Another major focus, as we saw in your report, is Ukraine.

What more is being said at the U.N. about that war?

NICK SCHIFRIN: The Security Council called a last-minute session this afternoon on Ukraine, during which President Volodymyr Zelenskyy spoke to foreign ministers and said, look, with so much focus on the Middle East, don't forget about Ukraine.

Secretary of State Antony Blinken focused on support given to Russia by North Korea and Iran.

But this is an incredibly important trip for Zelenskyy coming to the United States this week, because he will present what he calls his peace plan to President Biden, as well as former President Trump and Vice President Harris, this week in Washington.

But the fact is, Geoff, that peace plan, according to Andriy Yermak, Zelenskyy's top aide, last night, requires, one, membership in NATO, something that the U.S. and Europe do not support, two, permission to use long-range weapons, permission that the U.S. has not yet granted, and, three, authorization to use Russian frozen assets to pay for the war in Ukraine.

Geoff, the U.S. has not given that permission either.

GEOFF BENNETT: An important trip for Zelenskyy, as you say, also an important trip, Nick, for Iran's new president.

What did he have to say today?

NICK SCHIFRIN: Yes, Masoud Pezeshkian has been presenting himself as someone who can do business with the West and someone who wants to return to the 2015 nuclear deal known as the JCPOA, which promised Iran sanctions relief in return for freezing its nuclear program.

And he reiterated that statement today in the General Assembly, as heard through an interpreter.

MASOUD PEZESHKIAN, Iranian President (through translator): We are ready to engage with JCPOA participants if JCPOA commitments are implemented fully and in good faith.

Dialogue on other issues can follow.

The appropriate response to this message from Iran is not to impose more sanctions, but to fulfill existing obligations to remove sanctions, benefiting the Iranian people, hence laying the foundations for more constructive agreements.

NICK SCHIFRIN: But, this week, senior Biden administration officials have said that Iran has made too much progress in terms of its nuclear file since the Trump administration withdrew from JCPOA.

And they also expect to see behavior change by Iran.

That includes not supporting proxies around the region and not sending weapons to Russia for its war on Ukraine before any negotiations can happen.

And, Geoff, there's no sign that Iran is interested in making either of those changes.

GEOFF BENNETT: Nick Schifrin in New York tonight reporting from the U.N. General Assembly.

Nick, thanks, as always.