Trump and Biden took questions on how to deal with China more broadly amid transparency concerns with the Chinese government. After Biden said he would make China “play by the international rules,” Trump touted $28 billion in subsidies given to farmers during his administration affected by the U.S.-China trade war.

“First of all, China is paying. They're paying billions and billions of dollars. I just gave $28 billion to our farmers,” Trump said, before Biden interrupted, “That’s taxpayers' money.”

Given a chance to respond, Biden turned to families at home.

“There's a reason why he's bringing up all this malarkey. There's a reason for it. He doesn't want to talk about the substantive issues. It's not about his family and my family. It's about your family and your family is hurting badly,” Biden said.

“Are we going to be able to pay the mortgage? Who's going to tell her she can't go back to community college? They're the decisions you're making in the middle-class families like I grew up in Scranton and Claymont. They're in trouble. We should be talking about your families, but that's the last thing he wants to talk about,” Biden added.

Trump scoffed at Biden's answers and took the chance to define himself as not another “typical politician.”

“That is a typical statement,” Trump responded. “That's a typical political statement. Let's get off this China thing. He looks at the family around the table, just a typical politician. I'm not a typical politician. That's why I got elected. Let's get off the subject of China. Let's talk around sitting around the table. Come on, Joe. You can do better.”

Biden responded to reports that Russia and Iran obtained voter information as a part of an election disinformation campaign by saying that any country that interferes in American elections will "pay a price."

" They will pay a price. And it's been overwhelmingly clear, this election -- I won't even get into the last one -- this election, that Russia's been involved. China's been involved to some degree," he said.

"Now we learn that -- that Iran is involved. They will pay a price if I'm elected. They're interfering with American sovereignty," Biden added.

In a disturbing allegation, the FBI director and director of national intelligence announced Wednesday night that Russia and Iran have conducted counterintelligence operations secretly to obtain voter registration information about Americans, allowing them to directly reach out to voters in Florida and Alaska.

The director of national intelligence portrayed Trump as the victim of the attack, and did not mention Democratic voters that were targeted.
Biden went on to accuse Trump of being a "Russian pawn" and not speaking out for the country's actions.

"I don't understand why this president is unwilling to take on Putin when he's actually paying bounties to kill American soldiers in Afghanistan, when he's engaged in activities that are trying to destabilize all of NATO. I don't know why he doesn't do it, but it's worth asking the question," he said.

TRUMP'S CLAIM: "Frankly, (Biden) ran the H1N1, swine flu, and it was a total disaster, far less lethal, but it was a total disaster. Had that had this kind of numbers, 700,000 people would be dead right now."

FACT CHECK: While Trump is correct that the H1N1 virus was much less lethal than COVID-19, it is misleading to call the Obama administration's response a "failure."

The Centers for Disease Control and Prevention estimates up to 575,000 lives were lost to the swine flu worldwide. Of those, fewer than 13,000 were American, due in part to the Obama administration's "complex, multi-faceted and long-term response," the CDC later wrote. Thus far, COVID-19 has taken the lives of over 210,000 Americans, a little over eight months since the first known case of the virus was discovered in the United States.

"The team, in my opinion, in 2009, really demonstrated that the planning was worth it. Nothing is ever perfect. But I felt just so impressed and so proud of the job CDC did in 2009," Dr. Julie Gerberding, a CDC director during the George W. Bush administration, told ABC News.

-ABC News' John Verhovek

Before moving on to election security, Welker asked Trump about his recent public criticisms of Dr. Anthony Fauci.

"President Trump, this week you called Dr. Anthony Fauci, the nation's best known infectious disease expert, quote, 'a disaster.' You described him and other medical experts as, quote, 'idiots'. If you're not listening to them, who are you listening to?" she asked.

"I'm listening to all of them, including Anthony," Trump said. "I get along very well with Anthony, but he did say don't wear masks. He did say, as you know, this is not going to be a problem. I think he's a Democrat, but that's okay."

Fauci is registered as an Independent and said not to wear a mask at the start of the pandemic as the task force was concerned with having enough personal protective equipment for health care workers. Once the science became clearer, he recommended the practice.

Biden responded by saying it was Trump who panicked when the virus hit U.S. soil, not the American people, drawing on interviews with journalist Bob Woodward.

"Think about what the president knew in January and didn't tell the American people. He was told this was a serious virus that spread in the air and it was much worse -- much worse than the flu," Biden said. "Americans don't panic. He panicked."

The final topic of the night was climate change with Welker first asking each candidate how he would combat climate change and support job growth at the same time as president. Trump answered first.

"So we have the trillion trees program. We have so many different programs. I do love the environment, but what I want is the cleanest, crystal clear water, the cleanest air," Trump said, taking credit for the country's reduced carbon emission last year.

He went on to slam other counties air-quality and tout the U.S. by comparison.

"Look at China, how filthy it is. Look at Russia. Look at India. It's filthy. The air is filthy. The Paris Accord, I took us out because we were going to have to spend trillions of dollars, and we were treated very unfairly," Trump said, closing his two minutes by saying his administration has done an incredible job "environmentally."

When it was Biden's turn, he pivoted to the existential threat he says global warming poses to humanity and said the U.S. has a moral obligation to "deal with it" -- but said climate change also creates a prime opportunity for new jobs.

"Here's where we have a great opportunity. I was able to get both all the environmental organizations as well as labor, the people worried about jobs, to support my climate plan. Because what it does -- it will create millions of new good-paying jobs," Biden said. "Wall Street firms indicated that my plan -- my plan will, in fact, create 18.6 million jobs, 7 million more than his. This is from Wall Street. And I'll create $1 trillion more in economic growth than his proposal does. Not on climate, just on the economy."

Trump slammed Biden's response, claiming the former vice president's plan would cause a massive economic depression and deeming it a "pipe dream," before raising Biden's stance on fracking.

In the face of Trump's criticisms, Welker asked Biden directly, "Would you rule out banning fracking?"

"I do rule out banning fracking," Biden said. "We need other industries to transition to get to ultimately a complete zero emissions by 2025. What I will do with fracking over time is make sure we can capture the emissions from the fracking, capture the emissions from gas. We can do that and we can do that by investing money. It's a transition to that."

"Excuse me," Trump interrupted. "He was against fracking. He said it. I will show that to you tomorrow."

"Fracking on federal land, I said," Biden responded. "No fracking and/or oil on federal land."