US intelligence has warned Donald Trump of "real and specific" threats from Iran to assassinate him, his presidential campaign said in a statement Tuesday.

"President Trump was briefed earlier today by the Office of the Director of National Intelligence regarding real and specific threats from Iran to assassinate him in an effort to destabilize and sow chaos in the United States," Trump campaign communications director Steven Cheung said in the statement.

"Intelligence officials have identified that these continued and coordinated attacks have heightened in the past few months, and law enforcement officials across all agencies are working to ensure President Trump is protected and the election is free from interference," he added.

The campaign did not elaborate on the claims, which come as international pressure increases on Iran to reduce soaring tensions in Lebanon, where Israel has carried out a bombing campaign against sites belonging to Lebanese group Hezbollah which is backed by Tehran.

Iran rejected accusations that it is trying to kill Trump earlier this summer, shortly after a gunman opened fire at a rally in Pennsylvania, killing one person and wounding the presidential candidate.

Days after the July 13 assassination attempt, US media reported that authorities had received intelligence on an alleged Iranian plot against the Republican, prompting his protection to be boosted. Iran rejected the "malicious" accusations.

"If they do 'assassinate President Trump,' which is always a possibility, I hope that America obliterates Iran, wipes it off the face of the Earth - If that does not happen, American Leaders will be considered 'gutless' cowards!" Trump wrote on his social media platform, Truth Social, at the time.

It was not immediately clear if the threats referred to by the campaign Tuesday were new or the threats that had been previously reported.

The United States has also accused Iran of a hack targeting Trump's campaign, alleging Tehran is seeking to influence the 2024 election.

Earlier this month, US authorities said Iranian cyberattackers had offered "stolen, non-public" material from Trump's campaign to staff for his then White House rival, Joe Biden.

"Foreign actors are increasing their election influence activities" as Election Day in November approaches, the US statement said, singling out Russia, Iran and China as "trying by some measure to exacerbate divisions in US society for their own benefit."

The US agencies said the Iranian cyberattackers had also attempted to share the information stolen from the Trump campaign with US media organizations. It did not name the outlets.

Iran has also vehemently denied those accusations.

Trump's presidential rival, Democrat Kamala Harris's campaign said on August 13 that it too had been targeted by foreign hackers, but did not give an indication of which country was believed to be behind the attempt.

The United States goes to the polls on November 5. Polls show Trump and Harris, who launched her campaign after Biden dropped out earlier this summer, are neck and neck.