In Detroit, in the battleground state of Michigan, "ugly scenes" erupted when party supporters were denied access to the count room, the BBC's Lebo Diseko reports from the site.

About 30 people were blocked by officials.They were mostly Republicans but some Democrats also say they were denied entry. Detroit police were called to enforce the decision.

Election officials said they had to control the number of people in the room because of coronavirus. Democratic presidential candidate Joe Biden is projected to win Michigan.

Donald Trump's campaign is mounting a legal challenge there. Trump won in Michigan in 2016.

Image source, Reuters

With the election coming down to results in a handful of states, officials are cautioning that the outcomes is some areas will not be clear any time soon.

In Nevada, where projections are almost neck and neck, Deputy Secretary of State Wayne Thorley told the BBC's US partner CBS there would be no results coming on Wednesday and that they would post results on Thursday at about 09:00 (17:00 GMT).

On the BBC's results system, with 85% of the votes counted, Biden had a slender lead in Nevada of 7,647 votes.

As we reported earlier, Arizona is also not expected to report final results on Wednesday. With 83% of the ballots counted, Biden leads Trump by 51%-48%. Some US media have already projected it as a Biden win.

In the battleground state of Georgia, the elections director in Fulton County - the state's most populous county - said counting should be finished by the end of Wednesday.

“As long as it takes we’re going to be here, that’s why we’re bringing in fresh bodies,” Richard Barron told a news conference.

On the BBC's system, 92% of votes in Fulton County have been counted, 72% are for Biden and 27% for Trump. State-wide, with 94% of the votes counted, Biden is on 49% and Trump on 50%.

• Read our analysis of the results so far

Image source, Reuters

Joe Biden's speech delivered a confident message and talked about the importance of uniting the nation. "I'm not here to declare that we've won. But I am here to report, when the count is finished, we believe we will be the winners," he said.

Key states are still counting ballots, but the Democrat said he has already won the most votes of any presidential candidate ever.

That claim is true - as of 23:00 GMT on Wednesday, Biden has won 70.5 million voters - three million more than Trump's 67.2 million.

Former President Barack Obama had held the record for most votes - he won 69.5 million in 2008.

Of course vote counts rise with the US population at large, and Biden's boast comes in an election with near-record turnout. Trump benefited from this too - he won more votes than he received in 2016.

And as we know, winning the popular vote does not guarantee a candidate the White House - we'll stay watching those crucial states - Arizona, Georgia, Nevada, Wisconsin and Pennsylvania - in the coming hours and perhaps days to see how the votes tally up.

Donald Trump's campaign is seeking to stop vote counts in parts of Georgia - an important battleground state that has not yet been projected for either candidate.

The lawsuit alleges that a Republican observer saw a poll worker add 53 late postal ballots to a stack of ballots that arrived on time in Chatham County. In Georgia, ballots must be received before 19:00 on election day to be counted.

It's the fourth key state where the president has filed legal challenges. He has vowed to stop the count in places where he says ballots are "fraudulent". But he has not provided any evidence to support those claims.

• In Michigan, his campaign filed a lawsuit to stop officials counting ballots. Biden is projected to win in the state with a slim margin
• In Pennsylvania, Republicans are appealing against the state's decision to count ballots that are postmarked by election day but arrive up to three days later. Hundreds of thousands of votes are yet to be counted in the state
• In Wisconsin, the president's campaign said it has requested a recount "based on abnormalities seen" on Tuesday

Image source, EPA

We've been asking our readers for their most pressing questions about the election. Now it's our turn to respond.

Judy, from BC, Canada, asks: Pretty much everyone in the world is fed up with this "electoral college" nonsense. So how hard is it to just make US elections a majority vote and dump the college?

The US electoral system is laid out in the constitution, so changing it would require a constitutional amendment.

This would have to be approved by two-thirds of both the Senate and the House of Representatives, or the same proportion of state legislatures. This would then need to be ratified by three-quarters of states.

This is very unlikely to be successful, although there have been attempts to change the system in the past.

There is an ongoing effort by some states , externalto award their electoral votes to the winner of the national popular vote, no matter who wins there. This is a way off, but would effectively nullify the electoral college.

And if you want to learn more about this project - or send in a question of your own - click here.

Some news just in on the count in Arizona. Megan Gilbertson, with Maricopa County elections department, says final results are not expected for the state today. They’re still counting. Currently we're looking at around 83% of votes tallied, giving Biden a 51-48% lead in the race for the state's 11 electoral college votes. That's a significant lead, and some US media have already projected it as a Biden win.

Clive Myrie
BBC News, Pennsylvania

It was Republican lawmakers in Pennslyvania who refused to allow local authorities to count postal ballots earlier. The state can only start counting early votes on election day itself.

Now, with the count still going, there's chaos, anger and recrimination.

Conversations over breakfast this morning then going into dinner tonight reflect an election still in play here.

On Tuesday the ballots were counted into the night. There were still one million left to process by morning.

The Philadelphia city commissioner told us he wants it all to be over too.

Why all the problems? It's down to Covid-19.

Republicans were happy to vote in person on election day. Democrats not so much. It's thought they're behind the millions of postal ballots sent in.

And the process for counting those votes is long, as one vote officials explains:

"Open the outer envelope. Check the signature. Open another envelope. Then check the ballot".

And repeat. For millions of ballots.

Image source, Getty Images

Electoral workers in Pennsylvania will continue to work into the night, with "hundreds of thousands" of ballots likely to be overnight counted, the state's top election official Kathy Boockvar said.

Both candidates are anxiously awaiting results from Pennsylvania, a critical battleground state.

Boockvar said the counting was slightly ahead of schedule, but it will still be a matter of days before the "overwhelming majority" of ballots are counted.

Read More: Election results in maps and charts

Our group chat with Republicans and Democrats across the US has been very active for the last 24 hours. As Biden’s lead grows, some Republicans have become are resigned to the idea that he may win, and tuned in to listen to the former vice-president.Here’s what a few Republicans said after Biden’s remarks:“I'm impressed. The anxiety I felt has ebbed considerably after listening to him. Very good speech,” said Rom Solene.

And Sam Wight wrote: “I think his supporters need to watch this. I hope they actually follow what he says and ‘lower the temperature’. I’m ready to move forward but I don’t believe his supporters look at moving forward the same way that conservatives do.”

For the past 24 hours your WhatsApp may have been pinging away with friends and family firing updates to each other.

Well, we also set up a WhatsApp group - with 13 Trump voters and 12 Biden supporters. Together they watched the results come in.

Republicans were jubilant overnight - they flooded the group with pictures from cheering watch parties.

But the mood changed on Wednesday, as the US woke up to the news that Biden was leading in several key states.

Trump supporters challenged the election process - leading some Democrats to leave the group chat.

Read how the night and day unfolded on our WhatsApp group.

US-based clothing retailer Gap has deleted a tweet that showed a red and blue hoodie sweatshirt that was supposed to send a message of political unity as tense vote-counting continues.

"The one thing we know, is that together, we can move forward," said the tweet. The image of the hoodie would zip up when Twitter users clicked on it.

Image source, Twitter/Gap

The tweet, which was quickly deleted, led to online mockery.

"Yay, we can just walk sideways depending on the city we’re in," wrote influencer blogger Chrissy Teigen.

“The intention of our social media post, that featured a red and blue hoodie, was to show the power of unity," the company said in a statement.

"It was just too soon for this message. We remain optimistic that our country will come together to drive positive change for all.”

Barbara Plett Usher
BBC News, Delaware

Joe Biden’s remarks were aimed at putting his stamp on the contentious post-election environment.

He did not declare victory, but said when all the votes had been counted he was confident he’d be president. And now that Michigan has been called for his campaign, it’s looking even more likely that he will have the 270 electoral votes he needs.

He acknowledged the challenges from Trump, although he didn’t name the president. He framed them as an attempt to grab power. "We the people will not be silenced or bullied,” he said.

But he spent more time appealing for unity and healing, infusing with particular passion his standard stump speech for the nation to overcome partisan divides. He knows that will be extremely difficult even if he is declared president.

The Democrats had been hoping for a blow-out victory to give Biden momentum and a broad mandate. But the close results show how entrenched the divisions have become.

On the same day that Americans went to the polls, the country recorded more than 91,000 new Covid-19 infections - the second highest single day tally since the outbreak began. And on Wednesday, the country surpassed 100,000 cases, according to the Washington Post.

As the country remains by the gripped by neck-and-neck presidential race, it also faces unmitigated outbreaks in more than 20 states across the country.

Nearly 9.5 million cases have been reported in the US so far, and more than 233,000 Americans have died of the virus.

At rallies before election day, Donald Trump had suggested that the virus would not receive news coverage after 3 November - election day. But whoever wins the presidential election will be tasked with this intensifying public health crisis. Experts have warned that the case load and death toll will continue to rise as flu season coincides with the outbreaks.

Natalie Sherman
New York business reporter

The outcome of the presidential race remains unknown, but investors are betting business is a winner.

Stock markets recorded their biggest post-election leap in decades on Wednesday. That's because investors bet the closer-than-expected race would reduce the chance of big change for companies.

Health and tech firms, which are now seen as less likely to face regulation, led the gains.

Analysts said the likelihood of divided government meant a no-go for proposals backed by challenger Joe Biden, like higher taxes on companies, even if he emerges the victor.

On a call with reporters on Wednesday the Chamber of Commerce, a powerful business lobby, said results in state-level fights, like Uber’s victory in California over a worker protection law, also suggested voters were focused on “a pro-growth, pro-business agenda”.

Read more on how the markets reacted.

We've been asking our readers for their most pressing questions about the US election. Now it's our turn to respond.

Chinga from China asks: What happens if it's a tie?

There are 538 electoral votes up for grabs, with a fixed number of electors representing each state based roughly on the size of its population.

This means a draw is possible at 269 votes each, although very unlikely.

If no candidate gains a majority of votes in the electoral college, it would be over to the US Congress to decide.

It would be the members of Congress elected in the 2020 elections who would take on this responsibility.

• What is the electoral college?

The House of Representatives would vote to decide the president, with each state delegation having one vote - a majority of 26 is needed for a candidate to become president.

The Senate would choose the vice-president, with all 100 senators having a vote.

And if you want to learn more about this project - or send in a question of your own - click here.

Image source, Getty Images

Cori Bush, a racial-justice activist who was once homeless, has become the first black woman to represent Missouri in Congress. She won with about 79% of the votes to her Republican opponent's 19%.

Her district includes the cities of St Louis and Ferguson - where massive protests took place in 2014 after the police shooting of Michael Brown, an 18-year-old black man.

Bush was an activist leader during those Ferguson demonstrations.

An ordained minister and former nurse, she was backed by the Justice Democrats, a group that has campaigned for progressives, including New York Congresswoman Alexandria Ocasio-Cortez.

Her success in the Democratic primary earlier this year illustrates the growing influence of the party's left wing. She defeated William Lacy Clay Jr for the nomination, ending his family's decades-long hold on the seat.

After election day, ongoing ballot counts are used to predict - or "project" - the winner of each state.

A state will not be projected as being won by a candidate, however, until enough data has been collected to declare a clear winner. That includes months of polling, exit polls on the day and some of the actual votes counted.

Complicating matters this year is the spectre of prolonged vote counts in some places due to an unprecedented volume of early voting, plus the potential for legal challenges and a president stoking unfounded fears over mail-in ballot fraud.

US media still shiver to remember election night in 2000, when networks projected Al Gore winning the crucial state of Florida, only to pivot hours later and declare George W Bush president. But the margin was so slim, Gore conceded, then retracted his concession, leading to a month of legal and political wrangling.

This year the BBC gets its data from polling firm Edison Research who do the field work for the exit polls and work with US networks in the National Election Pool. The watchword from all this year is caution - there is no race to be first.

If the BBC and its partners don’t believe there is enough data to project a winner, we won’t do so - even if others are.

Anthony Zurcher
BBC North America reporter

Brick by brick, Joe Biden is rebuilding the Democratic electoral “blue wall” in the Midwest. Michigan is now in the former vice-president’s victory column - and US media are projecting a Wisconsin win too. That brings him tantalisingly close to the presidency, with multiple paths to the 270 votes necessary to secure an electoral college victory.

Pennsylvania is the remaining piece, and Biden continues to chip away at what once looked like a daunting lead for Donald Trump there.

Pennsylvania, however, is unnecessary. Biden could prevail simply by maintaining his leads in two western states, Arizona and Nevada.

Four years ago, Michigan was a shocking loss for the Democrats - an unexpected defeat that, while not the sole reason for Trump’s victory, was a bitter pill for the party to swallow. Part of Biden’s pitch to Democrats to be their presidential nominee was that he was well positioned to win back voters in places like Michigan. It took a while, but he proved up to the task.

• Read more on the paths the candidates have to victory.

The Trump campaign said it is suing to halt vote count in Pennsylvania, saying "Democrats are scheming to disenfranchise and dilute Republican votes".

The campaign also took aim at Pennsylvania's secretary of state - the official in charge of elections - who earlier said that voting in the state had been one of the "smoothest" she had witnessed.

In a statement, it claimed that Democratic officials were forcing observers to stay 25ft from the counting process, "leaving no meaningful way whatsoever for our observers to do their jobs".

Matthew Weil, director of the Bipartisan Policy Research Center's elections project, told the BBC he was most concerned about the dispute in Pennsylvania as the Supreme Court was deadlocked on a case brought by Pennsylvania Republicans about an extended mail-in ballot deadline.

This was before Justice Amy Coney Barrett joined. President Trump nominated her to replace Justice Ruth Bader Ginsburg, who died last month.

"I do think there is a risk that some of those [postal] ballots that were cast by election day and not received until Friday may be discarded," Weil said.

The Trump campaign also declared victory in Pennsylvania, despite there being incomplete results and no projections to suggest a win.

Michigan is projected to vote for Biden.

The state, with 16 electoral college votes, is a key battleground. Back in 2016, Trump won with a majority of only 10,704 votes – the narrowest margin of victory in Michigan's presidential election history, and the narrowest of any state in that year’s race.