Donald Trump has reportedly been exploring options to strike Iran's main nuclear site in the coming weeks.
The President was said to have asked top advisers about attacking the country's nuclear facilities, according to the New York Times.
The advisers reportedly warned Trump the move could spark war in his final two months in office and dissuaded him from going ahead with the military strike.
Trump's plan was aired during a meeting at the Oval Office last Thursday, with several top aides, including Vice-President Mike Pence, Secretary of State Mike Pompeo and the chairman of the Joint Chiefs, General Mark Milley, the newspaper said.
The outgoing Republican leader was reported to have asked "whether he had options to take action against Iran's main nuclear site in the coming weeks".
Officials told the newspaper that international inspectors reported a significant increase in the country's stockpile of nuclear material, which sparked Trump's concern.
A report from the International Atomic Energy Agency found that Iran now had a stockpile of more than 2442kg of low-enriched uranium, enough to produce about two nuclear weapons.
A likely attack would be on Natanz, where the agency reported that Tehran's "uranium stockpile was now 12 times larger than permitted under the nuclear accord that Trump abandoned in 2018", three years after it was signed in a bid to curb Iran's nuclear capabilities.
But Trump would have been long gone from office by the time Iran took the several months required to enrich the uranium to bomb-grade material.
The agency also reported inspectors were not allowed to look at sites suspected of holding uranium and other nuclear materials.
Former Defence official turned Democratic Michigan representative Elissa Slotkin said there would only be a few reasons to fire a secretary of defence with 72 days left in an administration.
"One would be incompetence or wrongdoing, which do not seem to be the issue with Secretary Esper," she told the Times.
"A second would be vindictiveness, which would be an irresponsible way to treat our national security.
"A third would be because the President wants to take actions that he believes his secretary of defence would refuse to take, which would be alarming."
Last month, Trump told Iran they had been "put on notice".
"If you f*** around with us, if you do something bad to us, we are gonna do things to you that have never been done before," he said during an interview.
Iran has long been Trump's pet peeve, and he first reintroduced sanctions and then tightened them even further after scrapping the nuclear accord.
European partners in the accord have struggled to keep the deal afloat despite Trump's efforts to torpedo it, and are hoping for a renewed diplomatic approach after the election victory of Democrat Joe Biden on November 3, although Trump refuses to concede his loss.
The Trump administration has pledged to step up the punitive measures, which some critics see as an attempt to build up a "wall of sanctions" that Biden would have difficulty tearing down once he takes office.
The latest meeting demonstrated how Trump still faces several global threats in his final weeks in office.
Increasing tensions with Iran will also harm Biden's chances to revive the 2015 Iran nuclear accord that Trump pulled out of in 2018, something Biden promised to accomplish within his term.