Washington CNN  — 

Vice President Mike Pence on Sunday reiterated President Donald Trump’s claim that there are doubts the order to shoot down a US drone by Iran was made at the highest levels.

“The President also had doubts as to whether or not the downing of our unmanned aircraft was actually authorized at the highest levels,” Pence told CNN’s Jake Tapper on “State of the Union.”

Pence said, “We’re not convinced that it was authorized at the highest levels,” and told Tapper he would not speak about the intelligence the US has related to the incident.

The vice president said after Trump was provided with casualty assessments for a retaliatory strike, the President “concluded that it was not a proportionate response to shooting down an unmanned American aircraft.”

Trump said Friday he called off an attack on Iran just as the US was “cocked & loaded” to strike because he decided there would be too many deaths for it to be a proportionate response to the downing of a US drone last week.

The US military targets were a limited set of Iranian radars and missile batteries, according to a US official with direct knowledge of the matter, who spoke on the condition of anonymity because of the sensitivity of the information. No US weapons had been launched when the decision was made to call off the strikes, which were first reported by The New York Times.

The US has been in a standoff with Iran, with US military or diplomatic responses having the potential to provoke further escalation.

Trump said Thursday he believes Iran probably mistakenly shot down the US drone, saying he finds it “hard to believe it was intentional.”

“Probably Iran made a mistake. I would imagine it was a general or somebody who made a mistake in shooting that drone down,” Trump said.

The President said that it made a “big, big difference” that the drone – which by definition is unmanned – had “nobody in” it.

CNN’s Jeremy Diamond, Barbara Starr and Jamie Gangel contributed to this report.