The intelligence about the Iranian plot was passed on by a human source

The US authorities obtained intelligence in recent weeks about a plot by Iran to try to assassinate former president Donald Trump, according to a CNN report. The development led to the Secret Service increasing security around the Republican presidential candidate, the report added.

However, there's no indication that 20-year-old Thomas Matthew Crooks, who attempted to assassinate Trump on July 13, was connected to the Iranian plot, CNN reported.

Trump, 78, survived the attempt on his life when the 20-year-old shooter fired multiple shots at him at a campaign rally in Pennsylvania, injuring his right ear. The male attacker was shot and killed by a member of the Secret Service.

Iran, meanwhile, termed the accusations as "unsubstantiated and malicious".

"From the perspective of the Islamic Republic of Iran, Trump is a criminal who must be prosecuted and punished in a court of law for ordering the assassination of General Soleimani. Iran has chosen the legal path to bring him to justice,” a spokesperson of the Permanent Mission of the Islamic Republic of Iran to the United Nations told CNN.

The intelligence about the Iranian plot was passed on by a human source.

Meanwhile, the Trump campaign, refused to share any detail over the threat and said all such questions should be directed to the United States Secret Service.

President Joe Biden appealed for the country to "unite as one nation" after the attempted assassination of his predecessor, Donald Trump, and said he was ordering an independent security review of how such an attack could have happened.

Biden delivered remarks from the White House after receiving a briefing on the investigation in the Situation Room. He called for a "thorough and swift" review and asked the public not to "make assumptions" about the shooter's motives or affiliations.

(With Inputs From Agencies)