AMNA NAWAZ: Welcome to the "NewsHour."

President Volodymyr Zelenskyy is in Washington tonight after a long day making the rounds on Capitol Hill, to the Pentagon and at the White House.

His goal?

Secure more armaments to repel Russia's 18-month invasion.

GEOFF BENNETT: But there is a growing chorus of skepticism and some hostility among House Republicans to the Ukrainians' requests, while, on the other side of the Capitol today, senators met Zelenskyy with open arms.

LAURA BARRON-LOPEZ: Today, a leader at war in Washington to rally support.

After bipartisan meetings with both the House and Senate, President Zelenskyy seemed optimistic about continued unity with the U.S. VOLODYMYR ZELENSKYY, Ukrainian President: We have great dialogue.

And I'm very thankful to you, to the journalists, to senators and Congress for helping us, support us.

We spoke about so many details, but it will be between us.

LAURA BARRON-LOPEZ: But, behind closed doors, an urgent plea.

SEN. CHUCK SCHUMER (D-NY): I'm quoting him verbatim.

Mr. Zelenskyy said: "If we don't get the aid, we will lose the war."

LAURA BARRON-LOPEZ: That aid hangs in the balance.

REP. KEVIN MCCARTHY (R-CA): Is Zelenskyy elected to Congress?

Is he our president?

I don't think I have to commit anything.

I have questions for him.

LAURA BARRON-LOPEZ: Support among some Republican members in the House, including Speaker Kevin McCarthy, is wavering.

Far right Republicans are opposed to sending what they call blank checks to Ukraine.

REP. KEVIN MCCARTHY: What is the plan for victory?

Where are we currently on the field?

The accountability issues that a lot of members have questions.

Just walk through that.

LAURA BARRON-LOPEZ: Meanwhile, support from both party leaders on the other side of Congress remains strong.

SEN. MITCH MCCONNELL (R-KY): These people in Ukraine who are fighting for their independence are taking on one of the two big adversaries we have, Russia and China.

It seems to me we ought to be helping.

SEN. CHUCK SCHUMER: Providing aid is not just a matter of Ukrainian security.

It's a matter of American security, because a victorious Putin is an emboldened Putin, making the world less safe for democracy.

LAURA BARRON-LOPEZ: Among the key things Zelenskyy asked for during his Capitol Hill visit, more air defense and long-range rockets, called ATACMS, which President Biden has been reluctant to provide.

Just before Zelenskyy arrived at the White House to meet with Biden, National Security Adviser Jake Sullivan said the president would not be sending ATACMS to Ukraine, for now.

JAKE SULLIVAN, U.S. National Security Adviser: To date, he has determined that he would not provide ATACMS, but he has also not taken it off the table in the future.

LAURA BARRON-LOPEZ: Later, at the White House, President Biden welcomed Zelenskyy and announced a new military aid package to Ukraine based on funds previously approved by Congress.

JOE BIDEN, President of the United States: Today, I approved the next tranche of U.S. security assistance to Ukraine, including more artillery, more ammunition, more anti-tank weapons.

And, next week, the first U.S. Abrams tanks will be delivered to Ukraine.

LAURA BARRON-LOPEZ: American aid now and in the future is critical to Ukraine's survival.

Early today, missiles rained over cities across Ukraine.

It was Russia's largest aerial bombardment in more than a month.

Some of the attacks targeted Ukraine's electrical grid for the first time in six months.

Ukraine's military says they shot down most of the missiles.

Still, falling debris ignited fires in residential areas in Kyiv and destroyed homes and businesses farther south in Cherkasy.

And in Southern Ukraine, projectiles destroyed a residential block in Kherson, killing five and wounding more.

Raising the stakes further, the Polish prime minister on television last night said Poland would stop sending military supplies to Ukraine.

MATEUSZ MORAWIECKI, Polish Prime Minister (through translator): We are no longer transferring weapons to Ukraine because we're now arming ourselves with the most modern weapons.

LAURA BARRON-LOPEZ: And just last week, Poland, Hungary and Slovakia announced a ban on Ukrainian grain imports, saying the move was to protect their farmers.

Back in the U.S., as Republican infighting over more aid to Ukraine continues, President Biden seeks to project strong support for a fellow democracy under brutal attack.

GEOFF BENNETT: And White House correspondent Laura Barron-Lopez joins us now from the White House North Lawn.

Also with us to discuss today's development, our congressional correspondent, Lisa Desjardins, at the U.S. Capitol, and, in Kyiv, reporting on the Ukrainian perspective, our foreign affairs and defense correspondent Nick Schifrin.

So, Laura, we will start with you.

President Biden met with President Zelenskyy.

What's the administration's message, as Congress debates more Ukraine aid?

LAURA BARRON-LOPEZ: Geoff, this is President Biden's sixth meeting -- sixth meeting with President Zelenskyy since the beginning of the Russian invasion of Ukraine.

And the White House message is simple, Geoff.

It's that the United States is going to stand behind Ukraine as long as it takes.

President Biden just announced a new security assistance package that they will give to Ukraine.

And that includes new air defense systems, specifically more ammunition for the HIMARS rocket launchers, which have reached far behind Russian lines, as well as additional cluster munitions and additional artillery.

Now, Geoff, Jake Sullivan of the National Security Council was telling reporters today that they are confident that, in addition to this security package, that Congress is going to pass more funding for Ukraine to provide resources as that war continues, despite the fact that there is ongoing chaos in Congress.

Jake Sullivan said that it is critical that some form of funding for Ukraine is passed by that September 30 deadline.

They're confident that it will be.

And Jake Sullivan said that, if it isn't, that that will create a lapse in the resources and in the supplies that the administration is able to provide to Ukraine.

GEOFF BENNETT: So, Lisa, Laura reports that the White House is projecting confidence that the Ukraine funding will happen.

Is that the sense that you're getting at the Capitol?

LISA DESJARDINS: No, Geoff.

Here, I can tell you Senate leadership sources in both parties who are actually pro-Ukraine sources tell me they do not think that funding can possibly pass by September 30 and may not even pass in whatever the first-round solution is to a potential government shutdown.

That is a short-term problem for sure for Ukraine, but there is also a potential long-term problem here, in that there is growing amount of questions, especially from House Republicans, about whether there should be any aid to Ukraine going forward at all or how much.

Now, that said, as Laura reported earlier, President Zelenskyy spoke to senators in that historic old Senate chamber.

And senators I talked to said he was powerful, he was strong.

He said he thinks Ukraine can win.

Speaking in English, he also said this will not be a forever war.

But sources I talk to here, Geoff, say they just aren't sure how long it will take for that win and how much American money it could take as well.

GEOFF BENNETT: Nick, as we mentioned, you're in Kyiv tonight.

Answer those congressional concerns that Lisa just raised.

Based on your reporting, how long and how much money could this take?

NICK SCHIFRIN: It is the crucial question for D.C., Geoff.

And when we speak to front-line soldiers and President Zelenskyy's aides about that, there's no clear answer.

They are still 100 percent focused on what they believe is their only goal, and that is reseizing all of their territory, no matter how long it takes and, at least in the short term, seizing enough territory in Southern Ukraine to threaten Russian supply lines and Russia's control over Crimea.

But that is a Herculean task because of massive Russian defenses.

And Ukraine is struggling to make progress in that key southern district.

We have seen some success from Ukraine in the last few days, recapturing the village of Klishchiivka outside of Bakhmut.

But that is in the east, and only after pitched battles turned the town into a moonscape, as you can see in this military video.

But in the south, where we spent the last week, some tens of billions of dollars of military aid have not overcome Russian minefields and those extensive Russian defenses.

So it's not clear what the path to victory is, but it is clear, Geoff, what the path to defeat is, and that's what Senator Schumer and President Zelenskyy were referring to today.

Ukraine cannot sustain the way it's been fighting if U.S. ammunition, supplies stop coming.

GEOFF BENNETT: Lisa, what do we know about the public support for your continued aid to Ukraine right now?

And does that influence the thinking of leaders on Capitol Hill?

LISA DESJARDINS: Yes, public sentiment often can be everything.

And if you look at recent polling, it shows you the kind of divide that we're feeling here at the Capitol.

Let's look at some numbers from CNN from July.

There, you can see Democrats.

Should we authorize additional funding?

Sixty-two percent said yes.

But Republicans, look at that; 71 percent of Republicans polled there say no.

As we like to stress here, no poll is perfect.

That's just a snapshot.

But that's exactly what we're feeling here, is that, in general, Republicans are the ones who are moving away from supporting Ukraine, a clear switch from the 1980s, of course, when Republicans were the ones leading the charge against Russia in the Cold War period.

And I will tell you this also.

Talking to some members, including many who are staunch allies of Ukraine, they say they're just not getting phone calls from their constituents on the phone this.

Adding to the problems and complications for Ukraine, Geoff, is that, of course, we're facing this government shutdown, a major budget crisis coming up.

And, really, just Ukraine and the importance of its funding seems to be getting lost a little bit in the lights here in Congress.

GEOFF BENNETT: Laura, as President Biden talks so often about the importance of defending Ukraine, he talks about threats to democracy abroad and here at home, where are his GOP rivals on this issue?

LAURA BARRON-LOPEZ: Well, the leading Republican presidential contenders are at odds with President Biden on this, Geoff.

Former President Donald Trump, who is leading the field by double digits, has questioned additional funding to Ukraine, has said that he alone would be able to fix this problem if he were back in the White House and hash out a deal between President Zelenskyy and President -- Russian President Putin.

But, again, there's no evidence that he would be able to do that.

And, also, the contenders right behind him, Ron DeSantis of Florida and Vivek Ramaswamy, are in line with Trump on this, questioning and again saying that saying that they don't think that more aid should be sent to Ukraine right now.

And that is where you're seeing a lot of those hard-line House Republicans draw their encouragement from, from these leading Republican contenders as they try to hold the line and say that they don't want to support Ukraine anymore.

But President Biden this week, and especially today, as he met with President Zelenskyy, has really tried to hammer home the point that the United States, despite what leading Republicans on the presidential field and despite what is being said among the House Republican Conference, that the United States is behind Ukraine and that all countries, all democracies across the world have a stake in this war that's ongoing right now.

GEOFF BENNETT: Final question to you, Nick.

You have been in Ukraine for the last two weeks.

You have been to the front lines.

What does the war look like right now?

NICK SCHIFRIN: Well, the violence continues not only in the front, Geoff, but also in the capital itself.

Today, Russia struck Kyiv, as well as half-a-dozen cities around the country, most worrying, as Laura reported earlier, strikes on Ukraine's electricity infrastructure.

U.S. and Ukrainian officials have been very worried about this because, last winter, Russia launched a campaign across many months against Ukraine's electricity infrastructure, and, for months, many millions of Ukrainians were without power and water.

And, in some ways, Ukraine's ready for it because it's been through it.

But U.S. and Ukrainian officials are worried that another campaign like that could sap some of the country's morale to continue to fight against Russia.

And the two things that have been keeping this country going, Geoff, are morale and those Western weapons that we have been talking about earlier.

GEOFF BENNETT: Nick Schifrin in Kyiv, Lisa Desjardins at the U.S. Capitol, and Laura Barron-Lopez at the White House, our thanks to you three for your reporting.