Kamala Harris has made her closing pitch for the US presidency at a historically Black church in the battleground state of Michigan while her rival Donald Trump embraced violent rhetoric at a rally in Pennsylvania.

Opinion polls show the pair locked in a tight race, with Democrat Vice President Harris bolstered by strong support among women voters while Trump gains ground with Hispanic voters, especially men.

Trump gave a profane and conspiracy-laden speech on Sunday, two days before the election, talking about reporters being shot and suggesting he “shouldn’t have left” the White House after his 2020 loss.

The Republican candidate repeatedly cast doubt on the integrity of the vote and resurrected old grievances about being prosecuted after trying to overturn his defeat four years ago.

Trump intensified his verbal attacks against a “grossly incompetent” national leadership and the US media, steering his rally in Lancaster, Pennsylvania, at one point on to the topic of violence against members of the press.

He noted the ballistic glass placed in front of him at events after a gunman’s assassination attempt in July at a rally in Pennsylvania.

“I have this piece of glass here,” he said.

“But all we have really over here is the fake news. And to get me, somebody would have to shoot through the fake news. And I don’t mind that so much.”

At one point he gestured to TV cameras saying, “ABC, it’s ABC, fake news, CBS, ABC, NBC. These are, these are, in my opinion, in my opinion, these are seriously corrupt people.”

It was the second time in recent days that Trump has talked about guns being pointed at people he considers enemies.

He suggested former Republican Liz Cheney, a prominent critic, wouldn’t be willing to support foreign wars if she had “nine barrels shooting at her”.

Less than 48 hours until election day, Trump continues to promote falsehoods about elections and argue that he can only lose to Harris if he is cheated, even though polls suggest a tight race.

Some of his allies, notably former chief strategist Steve Bannon, have encouraged him to prematurely declare victory on Tuesday even if the race is too early to call.

That’s what Trump did four years ago, kicking off a process of fighting the election results that culminated in the January 6, 2021, insurrection at the US Capitol.

Trump has joked about golfer Arnold Palmer’s genitalia, continued using sexist language and staged a rally at New York’s Madison Square Garden that included crude and racist insults that dominated headlines.

His campaign sought to clarify remarks he made on Sunday.

“President Trump was brilliantly talking about the two assassination attempts on his own life, including one that came within a quarter of an inch from killing him, something that the media constantly talks and jokes about,” campaign spokesperson Steven Cheung said in a statement.

“The [former] president’s statement about protective glass placement has nothing to do with the media being harmed, or anything else.”

Harris was campaigning on Sunday in Michigan, where she told a predominately Black church congregation in Detroit that God offers America a “divine plan strong enough to heal division”.

US election analysts reckon Harris would need to win about 45 electoral votes in the seven swing states to win the White House, while Trump would need about 51, when accounting for the states they are forecast to win easily.

The two major candidates offered starkly different tones with the campaign almost at an end, as Harris said voters can reject “chaos, fear and hate”.

Trump usually veers from subject to subject, a discursive style he has labelled “the weave”.

But outside the Lancaster airport, he went on long tangents and hardly mentioned his usual points on the economy, immigration and rote criticisms of Harris.

Trump referred to John Bolton, his former national security adviser and now a strident critic, as a “dumb son of a bitch”.

And he repeated debunked theories about voter fraud, alleging that Democrats could only win by cheating.

Public polls indicate a tight and competitive race across the battleground states that will determine the Electoral College outcome.

“It’s a crooked country,” Trump said.

“And we’re going to make it straight.”

Harris pushed back at Trump’s characterisations of US elections, telling reporters after the church service that Trump’s comments are “meant to distract from the fact that we have and support free and fair elections in our country”.

Those “good systems” were in place in 2020, Harris said, and “he lost”.

-AAP