WASHINGTON, Sept 26, 2024 (BSS/AFP) - Donald Trump said Wednesday Iran should be blown "to smithereens" if the Islamic Republic is involved in the harming of a US White House candidate or ex-president.

The provocative remarks come after US intelligence warned of threats from Tehran against the Republican's life after two apparent assassination bids in recent months.

"As you know, there have been two assassination attempts on my life that we know of, and they may or may not involve -- but possibly do -- Iran," Trump said at a campaign event in North Carolina.

"If I were the president, I would inform the threatening country, in this case Iran, that if you do anything to harm this person, we are going to blow your largest cities and the country itself to smithereens," he added.

Trump went on to say he and the United States have been "threatened very directly by Iran" and that a firm message needed to reach Tehran that there would be the most severe consequences should it be involved in plots to kill or hurt a US president or presidential candidate.

"The best way to do it is through the office of the president, that (if) you do any attacks on former presidents or candidates for president, your country gets blown to smithereens, as we say."

Trump also said it was "strange" that Iranian President Masoud Pezeshkian was in New York this week and accorded substantial protection as he attends the United Nations General Assembly even as news of the threats emerged.

"We have large security forces guarding him, and yet they're threatening our former president and the leading candidate to become the next president of the United States," Trump said, referring to himself.

The United States is obligated to extend security to foreign heads of state at the General Assembly under its treaty with the United Nations and its own laws.

- 'Credible intelligence' -

Trump's remarks come as world leaders scramble to try to avert hostilities between Iran-backed Hezbollah and Israel escalating into a wider regional war.

Iran has rejected accusations it is trying to kill Trump this summer, shortly after a gunman opened fire at a rally in Pennsylvania on July 13, killing one person and wounding the presidential candidate.

Days later, Trump posted on social media that if Iran did kill him, "I hope that America obliterates Iran, wipes it off the face of the Earth."

In a highly critical report on the security arrangements around Trump at the Pennsylvania rally, a US Senate committee noted that the deployment of elite US Secret Service countersnipers was made "in response to 'credible intelligence' of a threat."

On Wednesday, the 78-year-old Trump suggested the would-be assassin in Pennsylvania had used "potentially foreign-based apps," and that the alleged gunman in the second attempt in Florida had multiple mobile phones that Trump said US authorities have been unable to open.

"They must get Apple to open these foreign apps (and) open the six phones from the second lunatic," Trump said. "Because we have a lot at stake."

On Wednesday, US Attorney General Merrick Garland called the attempted assassination bids "abhorrent."

"Our nation has now experienced two assassination attempts against the former President in just the last three months. That is abhorrent," he said.

"The Justice Department will not tolerate violence that strikes at the heart of our democracy. And we will find and hold accountable those who perpetrate it. This must stop."

In August, the United States announced that it had foiled a plan by a Pakistani linked to Tehran to assassinate a US official in revenge for the death of Iranian general Qassem Soleimani, killed in 2020 in a US strike in Iraq ordered by then-president Trump.

US intelligence services have also warned of attempted cyberattacks on the presidential campaigns of Trump and rival Kamala Harris by actors it says are backed by Iran.