Washington — Secretary of Defense Mark Esper said he "didn't see" specific evidence that top Iranian military commander Qassem Soleimani was planning attacks on four U.S. embassies, but said he believed such attacks would have occurred.

"The president didn't cite a specific piece of evidence. What he said was he believed," Esper said Sunday on "Face the Nation." "I didn't see one, with regard to four embassies. What I'm saying is that I shared the president's view that probably — my expectation was they were going to go after our embassies. The embassies are the most prominent display of American presence in a country."

The president and his top officials have said the strike that killed Soleimani, the leader of Iran's elite Quds Force, was justified because there was an "imminent" threat to American service members and diplomats. Members of Congress, however, have raised questions as to the nature of the threat following briefings on the strike that the administration conducted with all members of the House and Senate.

Congressional Democrats have argued the intelligence they were presented did not demonstrate there was an "imminent" threat to U.S. personnel in the region, while some Republicans said the Trump administration was justified in killing Soleimani.

Mr. Trump told Fox News in an interview Friday that "it would've been four embassies" that were attacked, seemingly revealing more information about the nature of the threat.

Esper said he agreed that the embassies probably would've been targeted by Soleimani.

"What the president said was he believed that it probably and could've been attacks against additional embassies," he said. "I shared that view. I know other members of the national security team shared that view. That's why I deployed thousands of American paratroopers to the Middle East to reinforce our embassy in Baghdad and other sites throughout the region."

Esper said the U.S. had information that an attack would occur "within a matter of days that would be broad in scale, in other words more than one country, and that it would be bigger than previous attacks, likely going to take us into open hostilities with Iran."

Esper also pushed back on frustrations from Senators Mike Lee, a Republican from Utah, and Rand Paul, a Republican from Kentucky, who said after an all-Senate briefing Wednesday that Esper and other administration officials who briefed them on the Soleimani attack suggested they tamp down on debate and discussion regarding further military action in Iran.

"For every member that didn't like the brief, there were members who thought it was the greatest brief ever," he said. "That was never said, that they should not have debate, that they should not have a discussion."

Esper said he urged lawmakers to "be conscious of the messaging particularly to our troops because they are looking for messages — do they have the support of the American people while they are in harm's way?"