Reports: Trump's Secret Service protection boosted before assassination attempt due to Iran threat

July 16 (UPI) -- An unrelated assassination threat from Iran prompted U.S. Secret Service to increase former President Donald Trump 's security weeks before Saturday's assassination attempt in Pennsylvania, multiple media outlets reported Tuesday.

U.S. intelligence learned of an Iranian plot to assassinate Trump several weeks ago but have not found any ties with the shooting at a Pennsylvania rally where Trump was grazed by a bullet and a spectator was killed, three U.S. officials first told CNN , which was later reported by CBS and NBC News .

"Upon learning of the increased threat, NSC directly contacted USSS at a senior level to be absolutely sure they continued to track the latest reporting," a national security official told NBC News.

"USSS shared this information with the detail lead, and the Trump campaign was made aware of an evolving threat. In response, Secret Service surged resources and assets for the protection of former President Trump," the official added. "All of this was in advance of Saturday."

Trump's campaign would not elaborate on whether it was made aware of the Iran threat.

"We do not comment on President Trump's security detail. All questions should be directed to The United States Secret Service," the campaign said Tuesday in a statement.

The National Security Council added that there is no known link between the rally shooter Thomas Matthew Crooks, who was shot and killed by Secret Service, and the Iran threat.

"The investigation of Saturday's attempted assassination of former President Trump is active and ongoing," NSC spokesperson Adrienne Watson said in a statement. "At this time, law enforcement has reported that their investigation has not identified ties between the shooter and any accomplice or co-conspirator, foreign or domestic."

Trump is not the only target of the Iranian assassination plot, according to reports. John Bolton , Trump's former national security adviser, and former Secretary of State Mike Pompeo are also receiving tightened U.S. government security detail due to threats from Iran, which are "likely in retaliation" for the U.S. military's January 2020 killing of Qasem Soleimani, the commander of the Iranian military's Islamic Revolutionary Guard Corps .

On Tuesday, the Permanent Mission of the Islamic Republic of Iran to the United Nations denied the Iranian assassination plot, according to CNN.

"These accusations are 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," a spokesperson for the mission told CNN.

"Iran has chosen the legal path to bring him to justice."

While Trump frequently holds outdoor rallies, the former president and his new vice presidential running mate J.D. Vance announced Tuesday that they will hold their first rally together on Saturday, exactly one week after the assassination attempt, at an indoor venue in Grand Rapids, Mich.