US Democratic candidate Joe Biden is in Michigan and President Donald Trump is in Pennsylvania, states that could be key to winning the White House as the last weekend of campaigning hots up.
Mr Biden, joined by ex-President Barack Obama, said the US was "done with the chaos" of the Trump administration.
Mr Trump said there would be a "great red wave" of Republican victories.
Mr Biden has a solid lead in the polls, but his advantage is narrower in swing states that could decide the election.
More than 85 million people have voted early in the US elections, 55 million of them by post, setting the country on course for its biggest voter turnout in over a century.
Mr Biden and Mr Obama campaigned at a drive-in event in Flint, Michigan, before heading to Detroit where they were joined by singer Stevie Wonder. Mr Trump narrowly won Michigan in 2016.
In his first appearance on the campaign trail with his former vice-president, Mr Obama compared Mr Biden's character favourably with Mr Trump's.
"It used to be that being a man meant taking care of other people... not looking for credit but trying to live right," he said.
"When you elect Joe, that's what you'll see reflected from the White House."
Taking the stage, Mr Biden tore into his opponent, saying it was time for him to "pack his bags and go home".
"We're done with the chaos, the tweets, the anger, the failure, the refusal to take any responsibility," he added.
Mr Biden's campaign events have generally been small, as the candidate keeps rigorously to social distancing rules.
Not so for Mr Trump, who is holding a series of four rallies in Pennsylvania on Saturday.
At the first, in Newtown, he appeared on stage serenaded by chants of "Four more years!" and told the state where the US independence movement began centuries ago that "three days from now this is the state that will save the American dream".
He also joked about his recent brush with coronavirus, which also infected First Lady Melania Trump.
"At least those rumours that we don't live together proved to be false," he said.
After a rally of several hundred people - relatively small for him - the president flew to Reading, where thousands greeted him on the tarmac.
Mr Trump is planning another 10 rallies over the final two days of the campaign.
His campaign has five events in Michigan, Iowa, North Carolina, Georgia and Florida on Sunday, and then five more on election eve in North Carolina, Pennsylvania, Wisconsin and Michigan.
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