Joe Biden has dismissed claims by Donald Trump that he lacks the mental fitness to serve as president.
Joined by his running mate Kamala Harris in his first major interview since the Democratic convention, the former vice president laughed when asked whether he was - as asserted by the Trump campaign - “diminished”.
“Watch me. Mr President, watch me. Look at us both. Look at us both, what we say, what we do, what we control, what we know, what kind of shape we're in,” he said.
At 78 on inauguration day, Mr Biden would be America’s oldest ever president, should he win the election.
He would even consider seeking a second term, Mr Biden told ABC News anchor David Muir.
“I think it's a legitimate question to ask anybody over 70 years old whether or not they're fit and whether they're ready,” he said.
“But I just, only thing I can say to the American people, it's a legitimate question to ask anybody. Watch me.”
However he admitted that the party needed to work hard to promote up and coming talent within its ranks.
“We haven’t spent nearly enough time building the bench in the Democratic Party,” he said.
“So what I want to do is make sure when this is over, we have a new Senate, we won back statehouses, we’re in a position where we transition to a period of bringing people up to the visibility that they need to get to be able to lead nationally.
“And that's about raising people up. And that's what I'm about.”
The Republicans have sought to portray Mr Biden as a prisoner of the Democratic left and a supporter of campaigns to withdraw funding from police departments.
Support for the police has become a divisive issue in the election following the deaths of George Floyd and Breanna Taylor.
Anger at incidents of police brutality has fuelled demands from some activists for their budgets to be cut.
Mr Trump, whose election strategy includes focusing on law and order, has already secured the backing of New York City’s police union.
The former vice president said he supported police reform.
"I don't want to defund police departments,” he said.
“I think they need more help, they need more assistance, but that, look, there are unethical senators, there are unethical presidents, there are unethical doctors, unethical lawyers, unethical prosecutors, there are unethical cops. They should be rooted out.”
Stressing his own law and order credentials, Mr Biden added.
"Everybody forgets a third of that bill that I wrote was to put more cops in the street, not in their automobiles, but getting out and knowing the community -- knowing who owns the local grocery store, knowing everybody in the community, and crime will drop.”
It was the president who was responsible for cutting police budgets, Mr Biden added.
“So the only guy that actually put in a bill to actually defund the police is Donald Trump."
Mr Biden also said he would follow public health advisers' advice if they called for a national shutdown should he take office and the coronavirus had not abated.
"I would be prepared to do whatever it takes to save lives. We cannot get the country moving until we control the virus," Mr Biden said.
Asked specifically whether he'd push a national shutdown if scientists said it was necessary, Mr Biden replied: "I would shut it down."