The US president said he would sign off on the operation to kill Qassem Soleimani if Iran crossed his red line of killing an American, NBC News reported, citing five current and former senior administration officials.
The officials told the network the decision explains why an airstrike on Soleimani was one of the options the military presented to Mr Trump as a response to an attack by Iranian proxy forces on a military base in Iraq, which caused the death of a US civilian contractor.
“There have been a number of options presented to the president over the course of time,” one senior administration official told NBC News. They said the president’s aides put killing Soleimani on the list of potential responses to Iranian aggression “some time ago”.
The presidential directive, from June, could undermine Mr Trump’s assertion that the attack was carried out because Soleimani, the head of the Islamic Revolutionary Guard Corps’s elite Quds Force, was planning to attack four US embassies.
Several Democrats and a few Republicans in Congress have questioned the justification behind the attack, and said they have not been given adequate, detailed briefings.
Since the strike on Soleimani on 3 January, administration officials have claimed they acted because of an imminent risk of attacks on American diplomats and service members in Iraq and throughout the region.
On Friday, Mr Trump said Iran had targeted the US embassy in Baghdad and claimed it was aiming to attack four US embassies before Soleimani was killed.
“We will tell you probably it was going to be the embassy in Baghdad,” Mr Trump said in an interview on Fox News. “I can reveal that I believe it would have been four embassies.”
“What the president said was that there probably could be additional attacks against embassies. I shared that view,” Mr Esper said on CBS’s Face the Nation. “The president didn’t cite a specific piece of evidence.”
When pressed on whether intelligence officers offered concrete evidence on that point he said: “I didn’t see one with regards to four embassies.”
The Fake News Media and their Democrat Partners are working hard to determine whether or not the future attack by terrorist Soleimani was “eminent” or not, & was my team in agreement. The answer to both is a strong YES., but it doesn’t really matter because of his horrible past!
— Donald J. Trump (@realDonaldTrump)
In a separate interview on CNN’s State of the Union, Mr Esper said the administration had ”exquisite intelligence” saying a broader attack against multiple embassies was likely, but it could only be shared with the ”Gang of Eight,” a group of top congressional leaders who get briefed on sensitive information the rest of Congress does not have access to.
But House Intelligence Committee chairman Adam Schiff, a California Democrat and member of the Gang of Eight, said on Sunday that the group was not informed about possible attacks on four embassies.
“There was no discussion in the Gang of Eight briefings that these are the four embassies that are being targeted and we have exquisite intelligence that shows these are the specific targets,” he said.
Republican Senator Mike Lee said on Sunday he was worried about the integrity of information the president and security briefers have provided Congress about Iran.
“We were given somewhat general statements, and I believe that the briefers and the president believe they had a basis for concluding there was an imminent attack. I don’t doubt that. It is just frustrating to be told that and to not get the details behind it,” he said on CNN.
On Monday, Trump reiterated that the war general posed an imminent threat, but said that it did not matter either way because of “his horrible past”.
Additional reporting by agencies