Donald Trump said Friday he was ready to attack three Iranian sites on Thursday night but he called off the strikes after learning the assault would kill an estimated 150 people.

'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,' he said in tweets, 'not proportionate to shooting down an unmanned drone.'

He said, '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!'

At the White House a senior administration official said that Trump had over-ruled all his advisers and Pentagon chiefs when he called off the strikes.

'There was complete unanimity amongst the President's advisors and DOD leadership on an appropriate response to Iran's activities. The President made the final decision,' the official said.

Those advisors include Iran hawk John Bolton, Trump's national security advisor; Mike Pompeo, the Secretary of State who had been seen as more doveish than Bolton; and CIA director Gina Haspel.

Iran claimed that it had received a warning via the Gulf state of Oman that an attack was imminent and that Trump wanted to talk to Tehran directly. There was no confirmation of that claim from the U.S.

Donald Trump said Friday he was ready to attack three Iranian sites on Thursday night but he called off the strikes after learning the assault would kill an estimated 150 people

How the claims differ: Iran and the U.S. differ on where the drone was when it was targeted

U.S. side: Central Command released more details of the drone's activities, showing its flight path before it was shot down

It is unclear which Pentagon chiefs were advising Trump since his acting secretary of defense Patrick Shanahan leaves Friday after he was revealed to have defended his son who fractured his wife's skull with a baseball bat.

Trump had said Thursday that he believed someone 'loose and stupid,' possibly a general, ordered the strike on the Navy drone and he had a 'big, big feeling' that someone made a mistake.

'I have a feeling that it was a mistake made by somebody who shouldn't have been doing it,' he assessed.

Trump suggested that loss of life was a factor in his thinking then. 'We didn't have a man or woman in the drone,' he argued. 'It would have made a big, big difference.'

But he promised the U.S. would not leave the attack unanswered. 'This country will not stand for it, that I can tell you,' he said.

Instead he revealed the last-minute change of heart, while Iran said it could have shot down a P-8 spy plane at the same time it targeted the drone, claiming it would have killed 35 Americans by doing so.

There has been no confirmation of the P-8 being near the drone, although recently-released footage from the Pentagon of a tanker being targeted by what the U.S. says were Iranian Republican Guards, was taken from a P-8.

The drone incident aggravated fears of direct military confrontation between the longtime foes, and oil prices rose a further $1 per barrel to above $65.50 on Friday due to worries about possible disruptions to crude exports from the Gulf.

Lawmakers in the U.S. meanwhile encouraged Trump to take a 'measured' approach to answering the drone attack and warned him that Iran is begging for war.

Tehran said it doesn't want a military conflict and claimed it had issued two warnings to the Americans before shooting the spy plane down eight miles from its shores.

'Unfortunately, when they failed to reply... and the aircraft made no change to its trajectory... we were obliged to shoot it down,' Brigadier General Amirali Hajizadeh said.

Iranian state TV today showed off debris from the downed spy plane, including its fuselage, but none of the secret technology contained within.

Reuters reported that Trump sent a message via Oman to Iran calling for talks and de-escalation, but the Iranians are disputing information that appeared in the article.

'In his message, Trump said he was against any war with Iran and wanted to talk to Tehran about various issues,' an Iranian source told Reuters. 'He gave a short period of time to get our response but Iran's immediate response was that it is up to Supreme Leader (Ayatollah Ali) Khamenei to decide about this issue.'

The New York Times first reported that Trump that had authorized, and called off, airstrikes on Iranian radar and missile batteries.

Planes were in the air and ships were in position when the mission was called off - against the advice Secretary of State Mike Pompeo, U.S. National Security Advisor John Bolton and CIA director Gina Haspel, according to the report.

Trump had met with congressional leaders at the White House on Thursday afternoon.

House Speaker Nancy Pelosi, Senate Minority leader Chuck Schumer, Senate Majority Leader Mitch McConnell and other legislators with top security clearance attended.

Schumer said the told the president that conflicts like this tend to escalate unintentionally.

'The president may not intend to go to war here, but we are worried that he and the administration may bumble into a war. We told the room that the Democratic position is that Congressional approval must be required before funding any conflict in Iran,' he said.

He argued in favor of a 'robust, open debate' within Congress. He said Senate Democrats are pushing for a vote on an amendment that require congressional approval for defense dollars to be spent on a military conflict with Iran.

'It's supported by all Democrats in the Senate. We are asking leader McConnell to do the right thing and give us a vote next week on the NDAA on that amendment,' he stated.

Vermont Senator and Democratic presidential candidate Bernie Sanders said Friday that war would be a 'disaster' and Congress must 'assert its constitutional authority' to keep that from happening.

'A war with Iran would be a disaster and lead to endless conflict in the region. Congress must assert its constitutional authority and stop Trump from going to war,' he tweeted.

New Jersey Sen. Cory Booker, another Democratic presidential candidate, claimed that the Trump administration is on a 'clear march' to a war that it does not have the authority wage.

'This is not reality television, where decisions are made in the pursuit of maximum drama,' he said in a statement. 'The President together with his top officials have been bent on escalating an already tenuous situation in the Middle East, with no plan in place to de-escalate tensions.'

Booker said, 'This is a crisis of his own making — his reckless and erratic Iran policy is responsible for this combustible moment.

'Any military action in Iran that circumvents Congressional approval is a blatant and unconstitutional power grab.'

Freshman Democratic Rep. Alexandria Ocasio-Cortez told a reporter for CNN on Capitol Hill that Tehran is trying to provoke the United States.

'I think they're trying to goad us into a military conflict that's completely irresponsible,' she said Thursday afternoon.

Trump, pictured with Secretary of State Mike Pompeo, left, National security adviser John Bolton, center, and White House press secretary Sarah Sanders, is said to have approved military strikes against Iran in retaliation for downing a US drone but pulled back last minute

This grainy black and white footage shows the drone as it plummets from the sky

Iran released images purporting to show the fuselage of the wrecked US drone on Friday

The purported wreckage of the American drone is seen displayed by the Islamic Revolution Guards Corps in Tehran

A section of the destroyed warplane released by Iran, amid fears over what Tehran and its allies might glean from its inner workings

Tehran had claimed earlier in the day that it had 'indisputable' evidence the drone violated its airspace.

But the U.S. said the drone was shot down 21 miles off the Iranian coast, in the Strait of Hormuz.

Pentagon video footage showed a smoke trail from the $180 million surveillance aircraft following a missile strike on the drone it says was flying over international waters.

Amid the increasing fears of open conflict, Senate Majority Leader Mitch McConnell confirmed to Fox News that a 'measured response' would be coming from the White House.

In a statement, the top Republican in the House, Kevin McCarthy, and ranking lawmakers on security committees, Reps, Michael McCaul, Devin Nunes and Mac Thornberry, used similar language after the briefing with Trump and senior administration officials.

'There must be a measured response to these actions. President Trump and his national security team remain clear-eyed on the situation and what must be done in response to increased Iranian aggression,' they said.

'In Congress, we stand ready to support our men and women in uniform, our country, and our allies in the region.'

A section of the spy plane's fuselage lies on the floor after it was shot down just after 4am local time on Thursday

Debris from the wrecked drone was pictured by Iranian media as Trump asked for talks with the Supreme leader

Iran said it had recovered parts of a US spy drone in its territorial waters, after downing the aircraft in a missile strike slammed by President Donald Trump as a 'big mistake'

Iranian Supreme Leader Ali Khamenei next to Khordad-3 missile system last month - Trump has reportedly conveyed his demands to speak to the head of state

Trump gathered national security officials for a Situation Room meeting on Thursday afternoon. Haspel, Pompeo, Army Secretary Mark Esper and acting Defense Secretary Patrick Shanahan attended.

Shanahan arrived for the meeting with Trump holding a folder marked 'SECRET/NOFORN.'

Risks to Wall Street's rally abound despite record high The benchmark S&P 500 index hit a record high on Thursday as an almost giddy euphoria over the prospects of a U.S. interest rate cut fueled the appetite for equities, but there are plenty of pitfalls that could throw the stock market off course. It finished at a record closing high and the 10-year Treasury yield dipped below 2% for the first time in more than 2-1/2 years a day after the Federal Reserve signaled the potential for a rate cut as soon as its next meeting in July as it said it was ready to battle risks to the economy, including the U.S.-China trade war. Adding to the uncertainty for stocks are worries about a potential military confrontation between Tehran and Washington. Oil prices jumped more than 5% on Thursday after Iran shot down a U.S. military drone. Rising oil prices are a negative for stocks because they cut into consumer spending, said Quincy Krosby, chief market strategist at Prudential Financial in Newark, New Jersey. Advertisement

Neither the Pentagon nor the White House has commented on the briefing.

Trump has twice taken military action against targets in the Middle East - in Syria in April of 2017 and 2018.

Officials at the Pentagon are said to have warned of escalation and risks for American forces of expanding the military footprint in the region to Iran.

Massachusetts Senator and 2020 presidential candidate Elizabeth Warren told Trump on Thursday that he 'needs to step back from the brink of war' in a tweet.

She said, 'Donald Trump promised to bring our troops home. Instead he has pulled out of a deal that was working and instigated another unnecessary conflict.

'There is no justification for further escalating this crisis—we need to step back from the brink of war.'

Democratic Sen. Chris Murphy said, 'The place we have arrived at tonight on Iran is Donald Trump's choice. He chose escalation over diplomacy, without any idea how to get out of the downward spiral he set in motion.'

On Friday morning, the U.S. president blamed former president Barack Obama for the present situation.

He said, 'President Obama 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!'

A fragment on display at the Islamic Revolutionary Guards Corps headquarters in Tehran on Friday

Purported parts of the wrecked Navy spyplane at IRGC headquarters in the capital today

Debris lies on display tables before banners picturing the Naval spy plane and its alleged route into Iranian airspace

Trump tweeted the Iranian military 'made a very big mistake' when it shot down a spy drone

Timeline: Escalation in the Gulf region May 5: The U.S. says it is sending the USS Abraham Lincoln carrier group and a bomber task force to the Middle East because of a 'credible threat' from Iran. Since then Washington has announced the dispatch to the region of an amphibious assault ship, a Patriot missile battery and an extra 1,500 troops. May 8: Iran vows to enrich its uranium stockpile closer to weapons-grade levels starting July 7 if world powers fail to negotiate new terms for its nuclear deal. The U.S. responds by imposing fresh sanctions on Iran's steel and mining sectors. Smoke pours from the Norwegian-owned oil tanker on Thursday after it was hit by an explosion near the UAE and Iran in an apparent attack which has put the Middle East on high alert May 12: Two Saudi oil tankers and two other ships are damaged in mysterious 'sabotage attacks' off the coast of Fujairah, part of the United Arab Emirates. Washington believes Iran is to blame for the attacks, but Tehran denies involvement. May 14: Yemen's pro-Iranian Huthi rebels carry out drone attacks near Riyadh, shutting down a key Saudi oil pipeline. Two days later Saudi-led coalition air strikes hit the rebel-held Yemeni capital Sanaa. The next day the U.S. orders all non-emergency diplomats to leave Iraq, due to an 'imminent' threat from Iranian-linked Iraqi militias. May 19: Trump warns that if Iran attacks American interests 'that will be the official end of Iran'. Iranian Foreign Minister Mohammad Javad Zarif says the 'genocidal taunts' of U.S. Trump will not 'end Iran'. May 27: Trump says the U.S. is 'not looking for regime change' in Iran. May 30: Saudi Arabia - which accuses Iran of being behind the acts of sabotage and the drone attack in May - gets the backing of Arab leaders in its standoff with Tehran at summits organised by Riyadh. Iran accuses Riyadh of 'sowing division'. Inferno: A fire rages on board the oil tanker MT Front Altair after it was hit by an explosion in the Gulf of Oman on Thursday, in what has been described as a torpedo attack June 6: The UAE says a multinational investigation into the sabotage attacks point to the likelihood a state was behind them, without incriminating Iran. June 12: Japanese Prime Minister Shinzo Abe arrives in Tehran in a bid to mediate between Washington and Tehran. A Yemeni rebel missile attack on an airport at Abha, in southwestern Saudi Arabia, wounds 26 civilians. The Saudis accuse Iran of supplying the weapon. June 13: Two tankers, Norwegian and Japanese, are hit by explosions in apparent attacks in the Gulf of Oman. The U.S. Fifth Fleet says that it received two separate distress calls from the tankers in a 'reported attack'. Foreign Minister Zarif says the tanker 'attacks' as Abe visits are 'suspicious'. Mr Abe meets Iran's supreme leader Ayatollah Ali Khamenei who tells him: 'I don't consider Trump as a person worthy of exchanging messages with. I have no response for him and will not answer him.' Advertisement

Trump went on to confirm in tweets that he was ready to pull the trigger on strikes but pulled back when he learned the death toll would be high.

He said he decided that 150 deaths was a not a 'proportionate' response to an unmanned drone strike that resulted in no loss of American life.

He claimed new sanctions had been put on Tehran in retaliation. He did not say what they were, and Treasury had not announced new punishing actions as of Friday morning.

On Thursday evening the the Federal Aviation Administration issued an emergency order prohibiting all U.S. flights in over water area of Tehran-controlled airspace above Persian Gulf and Gulf of Oman.

This followed an earlier release by United Airlines that said it had suspended flights between New Jersey's Newark airport and the Indian financial capital of Mumbai following a safety review.

'Given current events in Iran, we have conducted a thorough safety and security review of our India service through Iranian airspace and decided to suspend our service between EWR and BOM,' United said on its website, referring to the airports.

Qantas, Air France and KLM announced later they would also avoid flights through the region.

Earlier Thursday the US suggested the drone - which has a wingspan wider than a Boeing 737 - was shot down 21 miles off the Iranian coast in the Strait of Hormuz.

Lt Gen Joseph Guastella, commander of U.S. Central Command air forces in the region, said: 'This was an unprovoked attack on a U.S. surveillance asset that had not violated Iranian airspace at any time.'

But the Islamic Revolutionary Guard Corps said it brought the drone down because it was 'violating Iranian air space' over the waters of Hormozgan province.

Iran's Foreign Minister Mohammad Javad Zarif provided coordinates to back the claim and said Iran would take the evidence to the United Nations.

'At 00:14 US drone took off from UAE in stealth mode & violated Iranian airspace,' Zarif tweeted. 'It was targeted at 04:05 at the coordinates (25°59'43'N 57°02'25'E) near Kouh-e Mobarak.'

'We've retrieved sections of the US military drone in OUR territorial waters where it was shot down.'

Central Command finally revealed their location for the drone as administration officials met for the hour long classified briefing with Trump in the situation room.

The Pentagon denounced the strike as an 'unprovoked attack' in international air space, claiming the navy drone was some 34 kilometers (21 miles) from Iran when destroyed by a surface-to-air missile.

Outgoing acting Defense Secretary Patrick Shanahan arrives for a meeting with President Donald Trump about Iran carrying a folder marked secret, at the White House

The US-made surveillance drone was brought down by Iran over the southern coastal province of Hormozgan, the Revolutionary Guard claimed

A handout TV grab made available by Iran state television English service press TV (PTV) reportedly shows Iran's surface-to-air missile system 'Khordad-3' as it launches to shoot down a US surveillance drone

Islamic Revolutionary Guard Corps said it brought the drone down as it was 'violating Iranian air space' over the waters of Hormozgan province