ABC's David Muir presses Biden on his claim 'negligence' has cost lives in pandemic

As he rails against the Trump administration's handling of the coronavirus pandemic, former Vice President Joe Biden has claimed government "negligence" has led to more deaths.

"People are dying because of this negligence, and it has to stop," Biden said in May.

Doubling down a month later, he told supporters that "tens of thousands of Americans have died needlessly because Donald Trump was slow to respond to the crisis and then when he did, he bungled the response."

During an exclusive interview, ABC "World News Tonight" anchor David Muir asked Biden, the presidential nominee, about those claims.

"More than 170,000 American lives lost now and Mr. Vice President, you have said that people are dying because of this negligence. Do you blame President Trump for lives lost?" Muir asked.

Biden told Muir that he doesn't blame the president for the virus, but for the government's response to it.

"I don't blame him for the COVID crisis. I blame him for walking away and not dealing with the solutions. The idea of saying that this is gonna go away, this miracle's gonna happen," Biden told Muir during his first joint interview with his running mate, Sen. Kamala Harris, D-Calif. "There’s all talk about the crazy things about bleach and using, I mean it's just, he hasn't listened to the scientists."

Muir then pressed on Biden's previous claims.

"But do you think the negligence on the part of this administration has cost lives?" Muir asked.

"I can tell you what Columbia University Medical School said. It said that he acted just one week earlier, he would have saved over 37,000 lives," Biden said. "Two weeks earlier, over 50,000 people...This is about telling the American people the truth, letting the scientists speak, listening to the science... and stepping out of the way."

Muir and "Good Morning America" co-anchor Robin Roberts conducted joint interviews with Harris and Biden -- their first since accepting the Democratic nomination -- which was featured in a special edition of "20/20" called "The Ticket: The First Interview," which aired Sunday on ABC.