Image source, Reuters

Now the debate is turning to the topic of childcare affordability. Trump is asked first what he would do to make childcare more affordable.

He responds by pivoting back to his attacks on Biden's track record on the US border.

Biden then hits back by defending himself, saying that Trump is the "worst president in American history", before saying that Trump did very little to make childcare more affordable.

Trump is given a chance to respond to the question again. He replies by defending his conduct as president.

"They rate me as one of the best, and if I'm given another four years I will be the best," Trump says.

Trump says he has "never seen anybody lie" like Biden, and again takes aim at him for his purported mishandling of veteran's affairs.

"Everything he does is a lie," he says.

Trump again also accuses Biden of destroying Social Security, saying that "millions of people" are being added to the public pension scheme.

"What they're doing to the VA [Department of Veterans Affairs] and to our veterans is unbelievable," he adds.

"Our veterans are living in the streets. And these people [migrants] are living in luxury hotels."

Image source, Reuters

Biden campaign officials say the president's raspy voice is result of a cold he's had over the last few days.

The campaign waited 45 minutes into the debate before sharing the president's condition with reporters.

According to statistics compiled by CNN, Trump is currently leading in speaking time, with 23 minutes and six seconds compared to Biden's 18 minutes and 26 seconds.

Both candidates are given an equal amount of time to respond to questions, although they do not necessarily have to use the entire time.

CNN will continue publishing these statistics every few minutes throughout the evening.

One Trump ally texted me early in the debate to claim Biden lost his train of thought during an exchange on Medicare.

He added that Trump was coming across calm and seems presidential.

This debate has indeed been pretty brutal for Biden.

But his campaign has been clear that he has no intention of stepping aside amid questions about his age.

This is America’s choice.

Trump has calibrated his performance for the TV screen. He's speaking forcefully, but not as bombastically as we typically hear him at his rallies.

Trump is also being more concise with his answers, when he tends to go off on lengthy tangents while on a campaign event stage.

Biden is taking aim at Trump on an issue that matters to many Americans - Social Security.

He says Trump wants to cut Social Security and Medicare benefits.

"He thinks there's plenty to cut," Biden says.

Image source, Reuters

Trump is asked about the climate crisis and the devastating effects of extreme heat, and what action he would take on the issue if he were elected.

He responds by saying that he wants clean air and water.

"And we had it," he says, claiming his administration had "the best environmental numbers ever".

But Biden argues against Trump's claims, noting the US backed out of the Paris climate accord under Trump.

With the ad break over, Biden is now being asked about disappointment from some black voters who say they have not seen progress on a number of issues, including maternal mortality.

Polls also show Biden has lost some support among black voters.

Biden says he doesn't blame black voters for being disappointed but says progress has been achieved for many black Americans, including less segregation in housing.

"We're going to do a whole lot more for black families," he says.

The half-time scorecardpublished at 02:57 28 June

02:57 28 June

Anthony Zurcher
BBC North America correspondent

Forty-five minutes into this debate, and Joe Biden has been on the ropes more often than not. Some of his answers have been rambling and unclear, which will only lend fuel to concerns by many Americans that he may be too old to be president.

But like a boxer on the ropes, Biden has started to take big swings against his opponent in an attempt to change the momentum.

A few of those swings may have landed, provoking former President Trump into angry responses. Biden, noting Trump’s conviction on charges that stemmed from an alleged romantic liaison with adult film star Stormy Daniels, said the former president had “the morals of an alley cat”.

“I didn’t have sex with a porn star,” Trump snapped back.

Trump also appeared on the back foot when talking about his response to the 6 January attack on the US Capitol.

But on the topic of the economy and immigration – the issues American voters say in polls are most important to them – Trump appeared confident and clear in his attacks on Biden’s record, while the president’s rebuttals were less effective.

“I really don’t know what he said at the end of that sentence, and I don’t think he did, either,” Trump quipped at one point.

More than halfway through the debate, that may be the line of the night so far.

The cocktails are flowing at one of the oldest restaurants in Las Vegas, once frequented by Frank Sinatra and The Rat Pack.

Tonight, the Italian American club is the venue for a Republican watch party. It has all the Trump trimmings, lots of MAGA red and diamonte hats at the dinner tables, and “Crooked Joe Biden” bingo cards are being handed out to keep guests entertained.

There’s no audience in the CNN studio where the debate is being held, but people watching here are clapping and cheering. Trump’s comments on immigration and the border get the biggest cheer so far.

“He can reach people through the TV camera”, says Trump supporter Delanne Ohlin. “He’s good at that”.

She believes what Donald Trump has to say about the economy will resonate with voters who are struggling with the cost of living.

“People go to a grocery store and see what’s going on. We’re on a fixed income, and prices affect us.”

Nevada has voted Democrat in the last four presidential elections, but only by narrow margins.

“I think he can win here,” says Delanne.

Fact check: Biden says no troops died under his administrationpublished at 02:53 28 June

02:53 28 June

The debate has cut to a commercial break, but earlier Biden claimed he is the only president in the last decade that doesn’t have "any troops dying anywhere in the world like he [Trump] did".

This is not true.

Three US service members were killed in a drone attack in Jordan in January this year.

And during the US withdrawal from Afghanistan in August 2021, 13 US service members were killed in a suicide attack at Kabul airport by IS-K, the Afghan branch of the Islamic State group.

According to figures by the Defense Casualty Analysis System, external, 65 US service members were killed in combat during the Trump presidency from 2017-20.

For the first time tonight, Biden brings up Trump's recent criminal conviction in New York on 34 counts of falsifying business records.

“There’s only one person that’s a convicted felon and I’m looking at him right now," he says.

Biden adds that Trump has the "morals of an alley cat" in reference to his alleged relationship with Stormy Daniels, a former adult film star, which Trump denies.

Image source, Reuters

Trump is asked to clarify his promise of "going after his political opponents".

He answers by saying that his retribution will be making the US a successful nation again.

Trump also brings up Hunter Biden's recent criminal conviction, and suggests that President Biden should also be a convicted felon "as soon as he gets out of office" for his "horrible" conduct as president.

"This man is a criminal," Trump says of Biden. "I did nothing wrong."

Biden responds that the equating his conduct with Trump's is "outrageous".

Trump is responding to Biden's attacks on him over 6 January, accusing him of egging on those who breached the US Capitol.

Trump says Biden has destroyed lives of so many people who were "so innocent".

He also attacks the House committee that investigated Trump's roles in the riot at the Capitol. He calls the panel the "unselect Committee" and claims they deleted information in their probe.

Image source, Reuters

Biden says Trump "encouraged" the rioters at the US Capitol on 6 January 2021.

He says the former president took no action for "three hours", while then-Vice President Mike Pence "begged" him to do something, and end it.

"Instead, he talked about these people being great patriots for America," Biden says.

Biden says the rioters should be in jail.

Trump is defending his actions around the 6 January 2021 riot at the US Capitol, when his supporters stormed Congress as lawmakers met to certify Biden's victory in the general election.

Trump rejects Biden's suggestion that he incited the mob to violence, pointing out that as well as urging them to fight, he asked that they march peacefully.

"I said 'peacefully' and 'patriotically'," Trump adds, before blaming then-House Speaker Nancy Pelosi and DC Mayor Muriel Bowser for allegedly turning down his offer of 10,000 National Guard troops.

In the past, Trump has referred to some of those jailed over the riot as "political prisoners" and vowed to review their cases if he takes office.

Image source, Reuters

Trump responds to the question on Gaza by saying that Israel should "finish the job".

He then says Biden has become like "a Palestinian", though points out that the president is unpopular among them.

He also brought up US support for Ukraine again, saying that European nations have spent less than America. He asks why Biden does not pressure Nato allies to put up more money.

Biden is now being asked about an issue that has divided some of his Democratic supporters: the war in Gaza.

He's asked what leverage he will use to get Hamas and Israel to end the war.

Biden says Hamas is the only one that does not want the war to end.

He reiterates strong support for Israel and says Hamas should be eliminated.

Image source, Reuters

During a tense exchange on the war in Ukraine, Biden warns that he believes Vladimir Putin is a "war criminal" who wants to re-establish part of the "old Soviet empire".

"Do you think he wants to stop there [Ukraine]?....what do you think happens to Poland, to Belarus, to those Nato countries?"

He also notes that the US gives Ukraine weapons - rather than money - saying Nato produces "as much for Ukraine" as the US has.

"That's why we're strong," Biden added.