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."

TRUMP'S CLAIM: "Nobody knew where it was coming from, what it was. We've learned a lot. But Anthony said don't wear masks. Now he wants to wear masks."

FACT CHECK: Dr. Anthony Fauci, one of the top infectious disease experts in the country, and other public health experts initially told Americans not to wear surgical or N95 masks in the early days of what has become the COVID-19 pandemic.

At the beginning of the pandemic, the Centers for Disease Control and Prevention and the World Health Organization, as well as Fauci and other top experts, initially discouraged wearing masks because of concerns that masks and other personal protective equipment were in short supply for health care workers who needed them. Public health officials were also concerned wearing masks could have unintended consequences if people touched their face more often to adjust them or fail to keep social distancing.

"There was this feeling that there would be a shortage just for those who really need them very early on," Fauci said in a recent interview. "That was the big deal. We didn't have enough PPE including masks. Then it became clear that cloth masks worked reasonably well. And therefore there was no more shortage. Then the different analyses, meta analyses and others came in that in fact, it does work."

In early April, the CDC changed its recommendation about face coverings for the general public, based on evidence that a significant number of people who were asymptomatic or not yet feeling sick were transmitting the virus.

Duke University researchers have also concluded that "if 95 percent of people wear cloth masks when within 6 feet of other people in public, it will reduce COVID-19 transmission by at least 30 percent."

Trump also said he thought Fauci was a Democrat, but Fauci is not registered as a member of any political party, according to D.C. voting records.

-ABC News' Stephanie Ebbs and Arielle Mitropoulos