US election results: Trump opens lawsuits as path to victory narrows
The Trump campaign challenges vote counts in the key states of Wisconsin, Pennsylvania and Michigan.
The Trump campaign is challenging vote counts in the critical states of Wisconsin, Pennsylvania and Michigan.
The BBC projects Mr Biden won Michigan. US media forecast he has won Wisconsin. No result has emerged in Pennsylvania.
Winning all three of these Rust Belt states would hand Mr Biden victory.
Mr Biden stopped short of declaring he had won the election, but said he was confident he was on course to defeat Donald Trump.
Overall turnout in Tuesday's election was projected to be the highest in 120 years at 66.9%, according to the US Election Project.
What are the campaigns saying?
On Wednesday afternoon, Mr Biden said in Wilmington, Delaware: "When the count is finished we believe we will be the winners."
He added: "I will govern as an American president. The presidency itself is not a partisan institution."
The Democratic challenger said he was feeling "very good" about Pennsylvania, although the campaign of Republican President Trump said it was "declaring victory" in the state on the count of "all legal ballots".
Senior Trump campaign aide Jason Miller said: "By the end of this week it will be clear to the entire nation that President Trump and Vice-President Pence will be elected for another four years."
Can Trump still win?
Mr Biden has the edge in the race to accumulate the 270 Electoral College votes needed to win the White House. The Democrat has 243 votes, while the Republican has 214.
In the US election, voters decide state-level contests rather than a single, national one. Each US state gets a certain number of electoral college votes partly based on its population and there are a total of 538 up for grabs.
If Mr Trump does lose Wisconsin (10 Electoral College votes), he must win Georgia (16 votes), North Carolina (15), Pennsylvania (20) and either Arizona (11) or Nevada (6) to prevail.
The president has a one-point lead in both North Carolina and Georgia and the two remain neck-and-neck with most votes counted in Nevada. The Trump campaign is hopeful it can still take Arizona.