Following the airstrike ordered by President Trump that killed Iranian Gen. Qassem Soleimani in Iraq, Fox News senior strategic analyst Gen. Jack Keane weighed in on Monday, saying that Iran's Supreme Leader Ayatollah Ali Khamenei – who had a close relationship with Soleimani – was left “shook.”

“This death of Soleimani has shook this regime the way nothing has in 41 years. Khamenei himself, I believe, is personally shook by it, stunned and surprised that it actually happened,” Keane told “America’s Newsroom.”

“And he's got the loss of his No. 1 executor of foreign policy, and successful foreign policy at that. And I believe it's going to have some impact on their decision-making in terms of what are they going to do,” he added.

TRUMP THREATENS IRAN WITH 'MAJOR RETALIATION' FOR FUTURE ATTACKS, WARNS IRAQ OF SANCTIONS IF US TROOPS OUSTED

Keane's comments came after President Trump warned Sunday that Iran could suffer a "major retaliation" if the rogue nation targets the U.S., as tensions continue to escalate in the Middle East after the U.S.-led airstrike killed Soleimani.

Iran has vowed to retaliate and avenge the death of the head of the Islamic Revolutionary Guard Corps' elite Quds Force.

However, Trump said Sunday of a potential attack: "If it happens, it happens. If they do anything, there will be major retaliation."

Iranian officials also announced they would be abandoning the 2015 nuclear deal, signaling threats of further nuclear proliferation.

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Keane said that Iranian officials did not expect the president of the United States to take such an action.

"[Trump is] promising them more if they take more action against American troops in the region or American diplomats. I think that gives them a pause in terms of what are they going to do. And they may not do something as bold as people are predicting them to do, because now this president has drawn a line that was never there before," he explained.

Fox News’ Vandana Rambaran contributed to this report.