Trump, 74, will hold two rallies in the battleground state of Florida, where opinion polls show a tight race. Biden, 77, will deliver a speech in his home state of Delaware on his plans for leading a recovery from the pandemic.
More than 49 million Americans already have cast ballots in person or through the mail, according to the University of Florida's Elections Project. That is more than one-third the total number of votes cast in 2016 — giving Trump, who is trailing in national opinion polls, fewer opportunities to change minds before voting ends on Nov. 3.
Trump has frequently criticized absentee voting as unreliable, and his campaign has fought state efforts to expand the practice, which analysts say is as secure as any other method.
Trump himself has voted by mail in past elections, but plans to vote in person in Florida on Saturday, the White House said.
RELATED: Where do Republican President Donald Trump and Democratic challenger Joe Biden stand on the issues? Here's a topic-by-topic look at the two major-party candidates for the Oval Office
Analysts gave Trump credit for a relatively restrained debate performance, but said it probably did not change the dynamics of the race in any fundamental way.
The pandemic has upended campaign traditions and its effects still are being felt. Americans may find themselves waiting days or weeks to know who won as election officials count tens of millions of mail-in votes.
Biden enters the final days of the race with more cash than Trump. The Democrat raised about $130 million during the Oct. 1-14 period, about three times the roughly $44 million raised by the Republican Trump's campaign, according to disclosures filed on Thursday with the Federal Election Commission.
In their debate on Thursday night, Biden renewed his frequent campaign-trail attacks on Trump's handling of the coronavirus pandemic, which has killed more than 221,000 people in the United States and cost millions their jobs.
U.S. Democratic presidential candidate Joe Biden and his wife Jill Biden arrive at New Castle Airport, following the final 2020 U.S. presidential campaign debate, in New Castle, Delaware, on Oct. 23, 2020. REUTERS/Leah Millis
"Anyone who's responsible for that many deaths should not remain president of the United States of America," Biden said.
Biden said Trump was too slow to warn the public about the severity of the pandemic and too quick to dismiss its threat, and had failed to develop a plan for recovery. Trump defended his handling of the health crisis, asserting the worst was over.
COVID-19 has emerged as the top issue in the race, and polls show Americans trust Biden more than Trump to handle the health crisis.
Trump pounced on a late-debate Biden remark that his environmental plan would transition the United States away from oil and towards renewable energy sources.
"He is going to destroy the oil industry," Trump said. "Will you remember that, Texas? Will you remember that, Pennsylvania?"
Biden's COVID-19 speech in Delaware on Friday follows his promises to improve access to testing and to listen to the advice of health officials and scientists, with whom Trump often feuds.
Biden has criticized Trump for returning to crowded public rallies, which usually feature little social distancing and few people wearing protective masks. Trump, who was diagnosed with COVID-19 in early October and spent three nights in the hospital, mocks Biden for his cautiousness.
Florida, Trump's next stop on the campaign trail, is a must-win for the president and among the battleground states likely to decide the election.
Both candidates have showered attention on, and made repeated visits to, the state, where a Reuters/Ipsos poll this week found Biden moving into a slight lead after being in a statistical tie a week earlier.
Trump will begin his visit to Florida at the Villages, a sprawling retirement center in central Florida that is a hotbed of political activity and a regular stop for Republican candidates.
Polls have shown Trump, who won voters above the age of 65 by 17 percentage points in 2016, to be running even or trailing Biden with senior voters in the state this year, a sign of possible trouble for the president.
RELATED: Read up on the latest political news leading up to Election Day
In the evening, Trump will hold an airport rally in Pensacola in Florida's heavily Republican northwestern panhandle, to urge supporters to vote early. Trump will spend the night in Florida before casting his own vote on Saturday in West Palm Beach.
Vice President Mike Pence cast his early-vote ballot in Indianapolis on Friday morning.
Former President Barack Obama, with whom Biden served as vice president for eight years, will campaign in Florida on Saturday, Biden's campaign said. Obama made his campaign-trail debut for Biden in Pennsylvania on Wednesday.
(Additional reporting by Andrea Shalal; Writing by John Whitesides and Andy Sullivan; Editing by Scott Malone, Howard Goller, William Mallard and Andrea Ricci)