President Donald Trump has explained his decision to call off airstrikes against targets in Iran because he was told 150 lives would be lost by one of his generals.
Trump said in a series of tweets that the US was "cocked and loaded" to strike Iran but that he stopped the attack after being told people would die.
He wrote: "On Monday they shot down an unmanned drone flying in International Waters. We were cocked & loaded to retaliate last night on 3 different sights when I asked, how many will die. 150 people, sir, was the answer from a General. 10 minutes before the strike I stopped it, not proportionate to shooting down an unmanned drone.
"I am in no hurry, our Military is rebuilt, new, and ready to go, by far the best in the world.
"Sanctions are biting & more added last night. Iran can NEVER have Nuclear Weapons, not against the USA, and not against the WORLD!"
The President also took a swipe at Barack Obama who he said made "a desperate and terrible deal with Iran."
"Gave them 150 Billion Dollars plus I.8 Billion Dollars in CASH! Iran was in big trouble and he bailed them out. Gave them a free path to Nuclear Weapons, and SOON.
"Instead of saying thank you, Iran yelled Death to America. I terminated deal, which was not even ratified by Congress, and imposed strong sanctions. They are a much weakened nation today than at the beginning of my Presidency, when they were causing major problems throughout the Middle East. Now they are Bust!"
Thursday's aborted plan was initially leaked by a US official who said the strikes were recommended by the Pentagon.
It was called off just before midnight, UK time, after Mr Trump had spent most of the day with top security aides and congressional leaders.
Asked how the US would respond to the attack, Mr Trump had said: “You'll soon find out.”
The planned operation was a stark reminder of the risk of military conflict between the US and Iran.
With tensions mounting in recent weeks, there have been growing fears that either side could make a move that leads to war.
The Trump administration has been combining a "maximum pressure" campaign of economic sanctions over Iran's nuclear programme with a build-up of American forces in the region.
The downing of the US drone over the Strait of Hormuz prompted accusations from the US and Iran about who was the aggressor.
Iran insisted the drone violated Iranian airspace while Washington said it had been flying over international waters.
Mr Trump had initially declared in a tweet: "Iran made a very big mistake!"
The President has repeatedly said he wants to avoid war and negotiate with Iran over its nuclear ambitions.
