Trump and Clinton make their closing arguments during final hours of campaigning

Both candidates are having a busy day of travel before polls open in the US

Trump and Clinton make their closing arguments during final hours of campaigning

Republican presidential candidate Donald Trump arrives to speak to a campaign rally, Monday, Nov. 7, 2016, in Raleigh, N.C. (AP Photo/ Evan Vucci)

With only hours to go until polling stations open, Donald Trump and Hillary Clinton have been making their closing arguments to voters.

Trump is relying on himself and a small group of 'surrogates' and family members to make the case for 'making America great again', while Clinton will leverage some star power in her late night campaign finale.

The former Secretary of State has released a blog post reflecting on what has been an often unpleasant race for the White House.

In her post on Medium, Clinton writes: "A lot of what we’ve seen and heard has been distressing, but we’ve also shared proud moments that remind us that we’re a country of fair-minded, big-hearted people.

"Millions of Americans  -  Republicans and Democrats alike  -  have stood up to say we’re better than this. And everywhere I go, I meet people who remind me of the diversity and determination that make this country great."

She adds that "tomorrow caps an amazing journey". She also released a final campaign ad, in which she speaks straight to camera without any cutaways.

Clinton will close out her campaign in Philadelphia, Pennsylvania, where she will be joined for a high-profile rally with President Obama, Michelle Obama and Bill & Chelsea Clinton. Bruce Springsteen and Jon Bon Jovi will perform at the event.

Donald Trump, meanwhile, will be joined by his vice-presidential candidate Mike Pence in Grand Rapids, Michigan for the final hours of the campaign.

It will round out a busy day for the Republican hopeful, with stops in Florida, North Carolina, Pennsylvania and New Hampshire also on the itinerary.

Allies such as Rudy Giuliani and Sarah Palin are out campaigning for Trump, as are family members including daughter Ivanka and his son Eric.

Trump released his key final campaign ad earlier than his opponent, in a dramatic video that focuses heavily on his familiar talking points such as corruption, immigration, and the political establishment.

"The only people brave enough to vote out this corrupt establishment is you, the American people," he argues to a cheering crowd.

Polls will start opening around the US from 6am local time tomorrow morning.

Opinion polls have continued to show Hillary Clinton enjoying a narrow leads - and her campaign will likely be encouraged somewhat by Sunday's announcement by the FBI that the Democrat has been cleared following its probe of recently discovered emails.

However, it's still all to play for, and both candidates have a good chance in several key swing states. It will not be long until we know for sure who will succeed Barack Obama, however: barring any controversy alá Florida in 2000, it'll be clear who's headed to the White House by the early hours of Wednesday morning.