Image source, Getty Images

We know that early voting in the US election has soared this year, with turnout so far already at half the 2016 total. Part of that is down to voters wanting to avoid potentially crowded polling stations during the coronavirus pandemic.

But strong engagement with who wins is also a factor, and there are signs voter participation could be the highest in a century.

Nearly 48 million of the 70 million votes already cast have been by post, external (the other option is in-person voting, where people cast their ballots at a polling station ahead of election day.)

But Donald Trump and some of his supporters have repeatedly tried to undermine the validity of postal voting.

On Tuesday the president said it would be “inappropriate” to take extra time to count mail-in votes, stating: "It would be very, very proper and very nice if a winner were declared on November 3, instead of counting ballots for two weeks, which is totally inappropriate and I don't believe that that's by our laws."

The huge number of ballots means they could take days or even weeks to count, experts say. However, the president is wrong to suggest it's illegal: states have until 8 December - known as the "safe harbor" deadline - to finalise their tallies.

Read more on how early voting will impact on the election.

Image source, Reuters

Joe Biden's running-mate Kamala Harris will be campaigning in the battleground state of Arizona today - on the same day as President Trump flies in to try to claim the polling lead back from Biden.

For her first stop, Harris will meet a group of Latina business owners in Tucson, then in the afternoon she travels to the city of Phoenix.

This will be Harris's second visit to Arizona in 2020, after she and Biden made their first campaign trip on 8 October.

It will be Trump's seventh trip, reflecting the tightness of the race in the state.

Donald Trump’s former National Security Adviser John Bolton has appeared on BBC Newsnight, and admitted he was worried about the president endangering American security.

Visibly riled when asked why he didn't voluntarily testify at President Trump's impeachment trial, he replied: "The fact is, the advocates of impeachment did a terrible job and made the situation much worse [...] the result of the impeachment was the empower Trump, not to constrain him."

Asked again why he didn't testify, he dodged the question by saying he wrote a book about what he knew which "has sold very well".

President Donald Trump's campaign website was hacked on Tuesday night to display an anti-Trump message.

"The world has had enough of the fake-news spreaded daily by president donald j trump", the hackers wrote.

The takeover lasted just half an hour, but it comes after a warning from US security officials of evidence that groups are trying to undermine the election. Campaign spokesperson Tim Murtaugh said that no data had been stolen and the site has been restored.

The messages on the website also claimed the poster had compromising information about the president and asked for donations to two Monero cryptocurrency accounts (cryptocurrency is a form of alternative online financial transaction that is difficult to track).

Image source, EPA

Today we'll be taking a close look at the presidential candidates' views on climate change, alongside breaking news from the campaign trail.

Donald Trump has offered a wide range of comments on the subject - from calling climate change "mythical" and "an expensive hoax" - to describing it as a "serious subject" that is "very important to me".

But to summarise:

President Trump is a climate change sceptic, and wants to expand non-renewable energy. He aims to increase drilling for oil and gas, and roll back further environmental protections. He has committed to withdrawing from the Paris Climate Accord - the international agreement on tackling climate change - which the US will formally leave later this year.

By contrast, Joe Biden says he would immediately re-join the Paris climate agreement if elected. He wants the US to reach net zero emissions by 2050, and proposes banning new leases for oil and gas drilling on public lands, as well as a $2tn investment in green energy.

Read how the candidates' climate change policies compare.

Democratic candidate Joe Biden is leading in the polls nationally - 51% of those asked say they plan to vote for Biden. Republican Donald Trump is trailing behind on 43%.

That's the national picture, but the US election is decided in a small number of states where the race is tighter. The polls suggest Biden has big leads in Michigan, Pennsylvania and Wisconsin - three industrial states his Republican rival won by margins of less than 1% to clinch victory in 2016.

See more in our US election poll tracker.

With six days to go until election day on 3 November, President Trump is keeping up his breakneck travel schedule with two airport rallies in the key battleground state of Arizona.

After staying overnight in Las Vegas, Nevada, Trump will head to Bullhead City, in the state's northwest near Nevada, then to Goodyear, outside the state's largest city, Phoenix.

Polls show Trump is narrowly trailing Biden in Arizona, which he won by 3.5 percentage points over Democrat Hillary Clinton in 2016.

If Biden can take the state, he will be the first Democratic presidential candidate to do so since Bill Clinton in 1996.

The former vice-president's plans for today include a briefing from public health officials. He will then give a speech near his home in Delaware, outlining his plans to fight Covid-19 and protect Americans with pre-existing health conditions.

Image source, Getty Images

• Donald Trump's campaign was temporarily hacked on Tuesday evening - officials say no sensitive information was exposed
• Trump will hold two airport rallies today in Arizona, where polls suggest he's narrowly trailing Joe Biden
• On Tuesday, Biden attacked Trump's record on coronavirus in two rallies in Georgia - the state typically votes Republican but Democrats hope it will switch this year
• The record number of people casting their ballots early has continued to grow. More than 70 million Americans have voted in person or by post, which is more than half the total turnout in the 2016 election
• But Donald Trump has again suggested it would be "inappropriate" to take extra time to count those early ballots sent by post - questioning the validity of the election
• With less than a week to go, Biden leads Trump nationally by approximately 7-12 percentage points, according to various national polls - but the race is tighter in battleground states that could swing the outcome

Good morning from the UK, and welcome to our live reporting on the US 2020 election. There are just six days to go until America decides if Joe Biden or Donald Trump will be their next president. We'll be bringing you the latest news and analysis from the campaign, and we'll also have an additional theme today: the US and climate change.

America is the world's largest carbon polluter (in terms of emissions per person), and how the candidates view the environment is one of the key differences between them. Stick with us for more on that and their policies later.