Katy Perry and Jon Bon Jovi perform in support of Hillary Clinton as Democrats bank on star power

Katie Perry and Jon Bon Jovi have both performed in support of Hillary Clinton, a day after Beyonce and Jay Z gave heartfelt speeches on stage alongside the Democratic presidential nominee.

Perry, 32, strode out to embrace Clinton in front of crowds at the key swing state of Pennsylvania, before performing hit single Roar and addressing prospective voters.

Shedding a blue coat to reveal a sparkly stars and stripes dress, she said:

"It's OK to have some fun and still change the world right? Shouldn't we have some fun whilst we make the world a better place?"

"I've been knocking on doors," she told the crowd. "A couple of weeks ago I knocked on college dorm rooms in Las Vegas. The smell was interesting," she quipped. "But I think we got the vote."

The I Kissed A Girl star is a longstanding Democrat, previously using her influence to campaign for Barack Obama, and has lent her support to Clinton, 69, for more than a year.

In September, the pop star raised eyebrows when she appeared to vote nude in a video for Funny or Die's satirical election series made in conjunction with Rock the Vote – aimed at mobilising young American voters.

But it was not only Clinton who received the star treatment, according to the BBC. Bon Jovi added his rock attitude to a Tim Kaine rally in Florida – with the vice-presidential nominee playing his harmonica on stage with the American icon.

The celebrity endorsements come at the end of a gruelling campaign battle between Clinton and Republican nominee Donald Trump, often dominated by personal insults and attacks.

Trump has closed the gap on Clinton after the revelation that the Federal Bureau of Investigation had reopened its investigation into Clinton's handling of classified information when she was US Secretary of State.

The development has kept Trump in the race, switching the media focus after the business tycoon spent weeks struggling with the fallout of a leaked video that featured him making sexist and misogynistic comments.

Clinton, addressing the Pennsylvania crowd only hours before Trump was rushed off stage in a security scare at a Nevada rally, said: "When you get knocked down, which everybody does, what matters is – get back up, stand up for what you believe, know the power of your own voice, it can change the world and let's once and for all, as we welcome her to the stage, let's prove that love trumps hate."