On Thursday, just days before the tenth anniversary of the Sept. 11 terrorist attacks, federal officials received a credible, but unconfirmed, threat to detonate car bombs in New York and Washington.
"This is the first, the first credible piece of information we've gotten," Biden said on NBC's Today Show Friday. "We cannot confirm it. We are doing everything within our power. All hands are on deck."
U.S. counterterrorism officials have been investigating the threat since the raid that killed Osama Bin Laden four months ago, Biden said.
The real worry, he added, is that it will be conducted by a single individual.
"The lone actor is the more worrisome thing because there are fewer trails to follow, there are fewer leads to move on," he said on the Today Show.
Biden advised Americans to continue their lives "as normal," but to be vigilant and report anything that may look suspicious.
"There are people who are likely to try over the next period of months and years, but the point is that we are using every single asset we can, including local law enforcement, to help thwart the possibility it could happen," he said.