Testifying before the Senate Armed Services Committee, Elbridge Colby said the strike that killed Khamenei and other senior Iranian leaders was not part of the American military campaign.

"Those are Israeli operations," Colby said, pushing back when pressed by lawmakers about whether regime change was an objective of US action.

Colby's restrained tone contrasted with that of President Donald Trump, who has framed the conflict in sweeping and triumphant terms since the strikes began.

"For 47 years, the Iranian regime has chanted death to America and waged an unending campaign of bloodshed and mass murder," Trump said Saturday.

In a social media post, Trump said Khamenei was "unable to avoid our Intelligence and Highly Sophisticated Tracking Systems" and that, "working closely with Israel, there was not a thing he, or the other leaders that have been killed along with him, could do."

The divergence in tone underscored broader questions about the administration's aims in Iran.

Secretary of State Marco Rubio said Monday that Washington acted only after learning Israel was preparing to strike, suggesting the US role was reactive rather than part of a broader plan.

Colby sought to narrow the scope of US objectives.

"The objectives of the military campaign... are focused on addressing the ability of the Islamic Republic to project military power against us, our bases, our forces, et cetera, as well as our allies and partners in the region and beyond," he said.

He described the primary targets as Iran's missile firepower -- which he said had grown substantially -- as well as its capacity to produce those weapons and elements of the Iranian navy.

Those goals, he argued, were "scoped and reasonable objectives that can be attained."

Pressed by Jack Reed, the panel's top Democrat, on how the killing of Iran's top leader fit with those objectives, Colby reiterated that he was "talking about the goals of the American military campaign," adding that the leadership strikes were Israeli actions.

While Trump has publicly urged the Iranian people to seize an "unprecedented opportunity" to overthrow the government, Colby maintained that the US military campaign is focused on degrading Iran's power projection capabilities - not explicitly on regime change.