President Donald Trump has instructed his national security team that any potential U.S. military action against Iran must deliver a swift and decisive action to the regime, rather than triggering a prolonged conflict lasting weeks or months, according to a U.S. official and several individuals familiar with internal discussions.

“If he takes action, he wants it to be conclusive,” one person briefed on the talks said.

However, advisers have not been able to assure Trump that Iran’s leadership would quickly collapse following an American strike, sources said. Officials are also concerned that the United States may lack sufficient regional assets to defend against what they expect would be a forceful Iranian retaliation.

These uncertainties could push Trump toward authorizing a more limited initial military operation, while keeping open the option to escalate if necessary — assuming he decides to proceed with any military action at all. Sources emphasized that the situation remains fluid and that, as of Wednesday afternoon, no final decision had been made.

During a visit to Detroit on Tuesday, Trump addressed Iranian demonstrators, saying “help is on its way,” and described the situation inside Iran as “fragile.”

When asked about the internal deliberations, a White House official referred to Trump’s remarks in the Oval Office on Wednesday. The president told reporters he had received intelligence indicating the Iranian government had halted the killing of protesters and suspended planned executions — actions Trump has previously suggested could provoke U.S. military intervention.

“We have been informed by very important sources on the other side that the killing has stopped and the executions won’t take place,” Trump said. “I hope it’s true. Who knows?”

Asked whether that meant military action was now off the table, Trump responded: “We’re going to watch and see how the process unfolds.”