Donald Trump claims he gave his order to kill Iranian general Qasem Soleimani because of a plot to blow up a US embassy.
The US President previously said Soleimani posed an imminent threat ahead of the US airstrike which marked his demise but had not fully expanded on that.
He told reporters today: "We caught a total monster and we took him out and that should have happened a long time ago.
"We did it because they were looking to blow up our embassy."
He also said there were other actions which prompted the move, adding: "We also did it for other reasons that were very obvious.
"Somebody died, one of our military people died, people were badly wounded just a week before.
"And we had a shot at him, and I took, and that shot was pinpoint accurate, and that was the end of a monster."
His comments come amid rising tensions in the middle east, as the US and Iran clash following the death of Soleimani.
The Iranian military leader was killed in a US-ordered strike over the weekend, which later prompted Iran to target and Iraqi base which homes American and British soldiers.
The US leader said nobody was injured in the retaliatory strike.
President Trump yesterday looked to ratchet down aggressions, stating the US would "embrace peace with all who seek it".
However, he has also postured over the strength of the US military, threatening severe repercussions for any further actions from Iran which target US citizens - having previously stated he might react "disproportionately" in such an instance.
He has also placed economic sanctions on Iran amid the tensions.
