President Donald Trump on Friday confirmed that he was "cocked and loaded" to strike Iranian targets but deemed the loss of life would be disproportionate to the downing of a U.S. drone.
"On Monday they shot down an unmanned drone flying in International waters. We were cocked and loaded to retaliate last night on three different sites," Trump said in a series of tweets.
The Times quoted a senior administration official as saying the operation was under way in its early stages — with planes in the air and ships in position — when it was called off.
The developments came as the United States and Iran continued to fight over whether the high-altitude U.S. surveillance drone had violated Iranian airspace when it was shot down Thursday.
On Friday, a senior official from Iran's Islamic Revolutionary Guard Corps claimed several warnings were issued before the drone was downed.
"We have had two stages of warnings," Cmdr. Amir Ali Hajizadeh said on state television. "They did not respond."
The aircraft was shot down after the last warning at 3:55 a.m. Thursday (7:25 p.m. ET Wednesday), he said. American officials did not respond to a request for comment on the Iranian claims.
The U.S. special envoy for Iran, Brian Hook, said Friday it was "important we do everything" to de-escalate tensions.
"Our diplomacy does not give Iran the right to respond with military force, Iran needs to meet our diplomacy with diplomacy and not military force," he told a news conference in the Saudi capital Riyadh.
Hesameddin Ashena, an adviser to Iranian President Hassan Rouhani, in turn called on Trump to ease sanctions.
"Today’s crisis stems from Washington’s withdrawal from JCPOA, and obstructing real diplomatic overtures," he said on Twitter, referring to the 2015 Iran nuclear deal. "But this process is reversible. Every tangible constructive step will be met in kind."
The incident has prompted the Federal Aviation Administration, or FAA, to prohibit most U.S. civil aircraft from flying in Iranian-controlled airspace over the Persian Gulf and the Gulf of Oman.
In a Notice to Airmen advisory, the FAA cited "heightened military activities and increased political tensions in the region, which present an inadvertent risk to U.S. civil aviation operations and potential for miscalculation or misidentification."
The notice applies to almost all U.S. carriers and commercial operators.
Other carriers also announced plans to halt flights over the Strait of Hormuz, including Dutch carrier KLM and Australian airline Qantas.
Trump signaled earlier Thursday that the United States was considering options for how to respond to the shooting down of the U.S. drone, an unarmed Global Hawk aircraft that can fly at up to 60,000 feet.
"Iran made a very bad mistake," Trump said. "The drone was in international waters, clearly. We have it documented."
The commander of the Revolutionary Guard Corps, Gen. Hossein Salami, said Thursday that the strike served as a signal that Iran wouldn't back down from threats.
"We have no intention of war, but we are standing strong," he said.
But Navy Capt. Bill Urban, a spokesman for U.S. Central Command, called the strike "an unprovoked attack," saying: "Iranian reports that the aircraft was over Iran are false."
Trump met with congressional leaders for about 90 minutes Thursday to discuss the situation in Iran. House Speaker Nancy Pelosi, D-Calif., said Friday that despite that meeting, she had no idea a strike was being planned.
"I did not receive any heads up that there was a strike that was in the works. Maybe the other leaders did on the Republican side, but I did not receive any of that," she told reporters. "But a strike of that amount of collateral damage would be very provocative and I'm glad the president did not take that."
Pelosi added that Democrats made clear in their meeting with Trump that he would need Congress to first approve any type of military action against Iran.
“Frankly if you’re going to make a strike, at least in my experience, you want to proceed with the strike as opposed to suddenly having your planes in the air and having to pull them back, as that can result in even greater miscalculations," he told the show.
As for what the Iranians' were aiming to do, Panetta said he was not sure either side has an "end game."
"That makes it even more dangerous because as it ratchets up on both sides, the danger of a serious miscalculation, bad judgement, could really produce a military confrontation," he said.
U.S. officials have also blamed Iran for what they said was an attack on two oil tankers in the Gulf of Oman last week. Iran has denied any involvement.
Acting Defense Secretary Patrick Shanahan announced Monday that the United States would send 1,000 additional troops to the region to address what he called air, naval and ground-based threats.
Alex Johnson reported from Los Angeles, Kristen Welker from Washington, and Ali Arouzi from Tehran.