Biden spoke at a high school in Wilmington, Delaware, where he took questions from reporters for the first time in months after delivering a speech attacking Trump's handling of the coronavirus pandemic. "And if he was briefed and nothing was done about this, that's a dereliction of duty".
Joe Biden is hiding in the basement and not saying anything.
While Biden's press conference in DE was ostensibly about how he would respond to the coronavirus pandemic, the former vice president also slammed the current White House occupant for his response to reports that Russian intelligence operatives offered to pay bounties to Taliban-linked militants who killed USA troops in Afghanistan.
The Associated Press has reported that at least one of Trump's daily intelligence briefings included evidence of Russian bounties. Trump has insisted that he was never briefed on such details because they weren't credible.
The Trump campaign did not immediately respond to a request for comment on the criticism. The former vice president added that he was considering asking for a classified intelligence briefing on the matter.
Biden is leading Trump by more than 9 points nationally, according to a RealClearPolitics average of recent polls. And he said, were he president, he would call Russian President Vladimir Putin and say, "Vladimir, old buddy, if any of this is true ... you've got a big problem".
Trump campaign spokeswoman Courtney Parella said Biden was "fearmongering and rooting against America's success" while Trump led a public and private-sector mobilization that had slowed the spread of the virus. He has said repeatedly that if Trump is reelected, North Atlantic Treaty Organisation will cease to exist in any meaningful form. Biden said Trump, 74, "doesn't seem to be cognitively aware", and he embraced the possibility of general election debates.
"I can hardly wait to compare my cognitive capability to the cognitive capability of the man I'm running against", Biden said. "What happened? Now it's nearly July, and it seems like our wartime president has surrendered, waved the white flag and left the battlefield". "It didn't have to be this way". And he added that widespread use of masks and social distancing practices must be come normal protocol for the "foreseeable future", and he warned that COVID-19 "will likely worsen" during the coming flu season.
"Clearly, we are not in total control right now", he said. "We can't continue half with a plan and half just hoping for the best. We can't defeat this virus with a piecemeal approach".
Biden said he has not been tested for the virus but expects to be tested "relatively soon", and he noted that Secret Service agents and staff who are around him are tested regularly.
Biden's campaign said separately that one of his first actions as president, if he wins, would be to ask Dr. Anthony Fauci, the federal government's leading infectious-disease expert, to continue serving.
On Tuesday, Mr Biden told reporters: "I'm going to follow the doc's orders - not just for me but for the country - and that means that I am not going to be holding rallies". He said that's necessary to restore the confidence that businesses, workers and consumers need to jump-start the economy.
Biden also emphasized personal protective equipment and investments in vaccine research and treatment methods.
"He called himself a wartime president". That, he said, is simply because Trump hasn't done his job. Trump later said he was invoking the act to ramp up production of ventilators, though he spent weeks arguing that governors should be responsible for securing their own supplies.