U.S.-Iran Crisis Live Updates: Trump Says Military Was Ready to Strike

In a series of tweets posted Friday morning, Mr. Trump said that American forces were “cocked and loaded” to strike three targets in Iran, but that he had called off the military action with 10 minutes to spare when a general told him that the attack would probably kill 150 people.

He added that he was “in no hurry” to attack Iran. “Our Military is rebuilt, new, and ready to go,” he said.

Mr. Trump also called the 2015 nuclear deal negotiated during the Obama administration a “desperate and terrible deal.”

The downing of an unmanned, $130 million American surveillance drone on Thursday by the Islamic Revolutionary Guards Corps brought tensions to the boiling point. President Trump ordered a retaliatory strike but backed away at the last minute, officials said.

Hostilities have intensified between the two countries since President Trump withdrew the United States from the 2015 nuclear deal with Iran and reintroduced economic sanctions.

[The U.S. has turned up pressure on Iran. See the timeline of events.]

Last week, United States officials said Iran was responsible for explosions on two tankers in the Strait of Hormuz, a vital passageway for much of the world’s oil. This week, Iran announced that it would soon breach a limit on nuclear material that it had agreed to in the 2015 deal, and soon after, the United States announced it would be sending additional troops to the region.

Now, both sides are trying to dominate the narrative about what happened to the drone, and what may happen next.

Russia is ready to help Iran barter oil for goods if the European effort to do so fails, but the extent of the help Russia could provide would probably make no difference to Iran, a senior Russian diplomat said.

Sergei Ryabkov, Russia’s deputy foreign minister, said that Russia was working with European and other nations on the barter mechanism, known by its acronym INSTEX. Designed by the European Union, the system was meant to allow countries to trade with Iran without being subject to American sanctions.

“We have been working on this and will continue to,” Mr. Ryabkov told a news conference in Sochi, Russia. “The only problem is that the volume we would receive as part of an ‘oil for goods’ arrangement is not a ‘game-changer’.”

Russia helped to negotiate the nuclear deal with Iran, and since the United States dropped out last year, has vowed to work with the other signatories to try to keep it alive. It considers American sanctions illegal.

The barter system was designed to get around sanctions by avoiding direct financial transactions or using the dollar, basically exchanging Iranian oil for medicine and food.

Mr. Ryabok said Moscow still hoped the European system would be implemented. “Common efforts are needed, and a lot depends on the Europeans,” he said. “I still hope for consensus on using the Instex mechanism for servicing oil transactions.”

Democrats seeking the party’s 2020 presidential nomination reacted with a mix of horror, anger and stupefaction to Mr. Trump’s handling of the Iran crisis. Gov. Jay Inslee of Washington said Mr. Trump’s actions amounted to “governing by chaos.” Representative Tulsi Gabbard of Hawaii, who is an Army National Guard veteran, warned that war with Iran was “HIGHLY likely unless Trump swallows his pride & returns to the Iran nuclear agreement he tore up.”

Senator Elizabeth Warren of Massachusetts urged restraint, saying, “There is no justification for further escalating this crisis.” And Senator Bernie Sanders of Vermont called on Congress to “assert its constitutional authority and stop Trump from going to war.”

Mr. Trump’s authorization of a strike and prompt reversal exposed divisions within his own party over the use of military force.

On one side was Representative Mike Gallagher, Republican of Wisconsin and a member of the Armed Services Committee, who warned that without some sort of retaliatory action, the United States risks “a massive deterrence failure in the region and it will only embolden Iran.”

“Unless Iran responds and says this was actually a huge accident on our part and we are prepared to negotiate, we have to respond,” Mr. Gallagher said, ticking off other possibilities like new sanctions or cyber attacks if the president does not want to use force. “A tweet is not, like, a response.”

He added, “Simply saying we are going to do something and then not doing it, to me, then you’re in no man’s land. That’s where Obama lived for eight years and it’s a bad place to be.”

On the other side was Representative Matt Gaetz, a Florida Republican closely aligned with Mr. Trump, who showered praise on the president’s restraint.

“I am grateful that the president is not eager to lurch into another Middle Eastern regime change, in an endless, unfocused, unconstitutional way,” he told reporters. “President Trump ran as a very different kind of Republican, someone who wanted to end wars not start them. And I think he is utilizing appropriate caution.”

The tensions between Iran and the United States had led international diplomats to call for a calm and considered approach from both countries.

Sergei Ryabkov, Russia’s deputy foreign minister, called the situation “a balancing act on the edge of war.”

“It is absolutely evident from the incoming information that the situation is extremely dangerous,” he told Russian news outlet TASS. “The menace of a conflict is not gone, and we once again are calling on responsible parties, if any are still left in Washington, to weigh all the consequences. We warn against incautious steps.”

The United Nations secretary general, António Guterres, also issued a statement on the situation in the Gulf.

“I have only one strong recommendation: nerves of steel,” he said, according to Alessandra Vellucci, a United Nations spokeswoman.

Europe has found itself stuck between the United States and Iran as their dispute escalates, and officials are still working to preserve the 2015 Iran nuclear deal that the United States withdrew from last year.

Chancellor Angela Merkel of Germany, speaking to journalists in Brussels after a European Union summit meeting, said the bloc’s foreign policy advisers had discussed the situation.

“We’re concerned,” she said, but added that there was still hope and trust for “a diplomatic, political solution in a very tense situation.”

Prince Khalid bin Salman, Saudi Arabia’s deputy defense minister, said on Twitter that he met with Brian Hook, the United States envoy on Iran, to discuss escalating the tensions.

Until President Trump took to Twitter on Friday morning, American officials were largely quiet in the immediate aftermath of the strike. But the Iranian authorities have spent much of the day working to define the narrative of what happened to the American drone, including displaying what officials said were fragments of the aircraft.

A Revolutionary Guards commander said on Friday that Iran had refrained from shooting down an American military plane that was accompanying the drone.

“With the U.S. drone in the region there was also an American P-8 plane with 35 people on board,” Gen. Amir Ali Hajizade, the commander of Iran’s Aerospace Force, said, according to the Tasnim news agency. “This plane also entered our airspace and we could have shot it down, but we did not.”

General Hajizade earlier told the Iranian state broadcaster IRIB that his forces had issued “repeated warnings” to the drone before a surface-to-air missile was fired at it on Thursday.

The same news outlet on Friday released a series of photographs that it said showed the retrieved fragments of the American drone.

Iranian state-run news outlets posted footage that they said showed the moment an Iranian air defense system shot down the American drone early Thursday.

In the clip, a missile can be seen being fired from a Khordad 3 air defense system of the Islamic Revolutionary Guards Corps, and a few seconds later, an explosion can be seen in the sky. Neither the video or the photographs reveal much about the nature of the strike.

Prime Minister Benjamin Netanyahu of Israel has been pushing for a hard-line stance against Iran, but one that stops short of war.

Ram Ben-Barak, a former deputy director of the Mossad and a member of Benny Gantz’s centrist Blue and White party, described the Iranians in a radio interview as “clever” and said they had already succeeded with their goal.

“The Iranians are pretty successful in their policy of walking on the edge, which is waking everyone up,” he said. “They are not only interested in the Americans, they are interested in involving the other players who can pressure the Americans.”

Giora Eiland, a retired major general in the Israeli Defense Forces and a former head of Israel’s National Security Council, argued that Mr. Trump played things perfectly with his last-minute pullback.

The public disclosure that Mr. Trump had called off the mission “creates a credibility to the threat,” he said in an interview, and now the Iranians “are very frightened today” about the possibility of American retaliation.

But Shimrit Meir, a Middle East analyst, saw things differently. Mr. Trump’s approach was “was just all over the place,” she said, and could ultimately be counterproductive.

“The way it was leaked suggests they wanted to send a message to the Iranians, that we refrained from doing this this time but this is the last and final warning,” she said in an interview. Adding, “But it’s not how it’s being received in the region.”

She also worried about what a broader conflict between the United States and Iran would mean for Israel in the long run, fearing that the recent events were a beginning, not an end. “If things escalate,” she said, “we are going to be the first ones to suffer the consequences.”

On the heels of American security warnings, several international airlines announced on Friday that they had diverted flights that cross Iranian-controlled airspace.

The Federal Aviation Administration issued an emergency order early Friday that prohibited all American flights in Tehran-controlled airspace above the Persian Gulf and Gulf of Oman because of “heightened military activities and increased political tensions.”

United Airlines said in a statement it had suspended its service between Newark Airport in New Jersey and Mumbai, India, that travels through Iranian airspace after conducting “a thorough safety and security review.” Customers planning to travel to Newark from Mumbai are to be rebooked on alternative flights to the United States.

The German carrier Lufthansa said in a statement that its planes would not fly over the Strait of Hormuz and that the diversion area was likely to expand. The Dutch airline KLM has also diverted flights as a precautionary measure because of the “incident with the drone,” it said in a statement.

Qantas Airlines of Australia said in a statement that it would be rerouting flights to avoid the Strait of Hormuz and the Gulf of Oman, which would affect its flights between Australia and London. British Airways said it was also taking similar measures in line with the F.A.A. advisory.

Oil prices are reflecting security concerns about the Persian Gulf. Brent crude, the international standard, has risen about 5.8 percent since the drone was shot down, trading at about $65 a barrel Friday morning. That is below the recent high of about $72 a barrel in mid-May.

About a third of the world’s crude oil and other petroleum products carried by tanker pass through the region, and incidents in the Gulf have caused the tanker companies to proceed with caution.

One executive at a company that operates a large global tanker fleet, speaking on condition of anonymity to discuss confidential business matters, described a sudden “drying up” of transactions in the region, with some companies saying they would stay away for now.

The Norwegian shipping company Frontline, whose Front Altair tanker was attacked on June 13 in the Gulf of Oman, said this week that until “the security of this important shipping lane is secured, Frontline will exercise extreme caution when considering new contracts in the region.”

Robert MacLeod, Frontline’s chief executive, said in an email on Friday that the company took “immediate actionafter its ship was attacked. “We stopped some of our vessels in the area, and only recommenced trading once increased security was in place.”

European leaders are scrambling to preserve the 2015 nuclear deal that the United States withdrew from last year, laying the groundwork for the current standoff.

Both Iran and the European signatories of the deal have made efforts to sustain it in the face of renewed American sanctions. Crisis talks are scheduled to take place in Vienna on June 28, even after the Iranian foreign minister, Mohammad Javad Zarif, said on Friday that Tehran would move forward with plans to reduce compliance with the agreement. The downing of the drone has further complicated efforts to save the deal.

Asked about the tensions, President Emmanuel Macron of France said on Friday that “we absolutely need to avoid escalation in the region,” but added that countries needed to remain committed to regulating Iran’s nuclear activity.

Guillaume Xavier-Bender, an Iran expert with the German Marshall Fund in Brussels, said that the United States, having withdrawn from the nuclear deal, appeared to have “no real plan or strategy on Iran.”

“No one understands the goal,’’ including Iran, he said.

“Do the Americans want regime change, or a photo op, or negotiations,’’ and on what terms, Mr. Xavier-Bender said, adding, “Europeans are trying to preserve the situation without knowing what the end game is.’’

Iran’s takedown of an RQ-4 Global Hawk surveillance drone on Thursday was not the first time the Iranians have outfoxed an unmanned surveillance aircraft used by the United States.

In December 2011, an RQ-170 Sentinel, a smaller, bat-winged drone, disappeared after takeoff from a base in Afghanistan. It either crashed or was forced down in northern Iran, nearly intact.

The Iranians claimed they had hacked the drone’s avionics and guided it to a controlled landing. The Americans attributed the loss of the drone to a technical malfunction.

Iran rejected President Barack Obama’s request to return the drone. Instead Iranian scientists dissected it with the aim of reverse-engineering the drone’s capabilities. The semiofficial Fars News Agency claimed at the time that Iran’s armed forces had captured a prize that could “blunt the U.S. technological edge over its adversaries.”

David D. Kirkpatrick, Megan Specia, Steven Erlanger, Rick Gladstone, Matina Stevis-Gridneff, Stanley Reed, Neil MacFarquhar, Michael Wolgelenter, Nick Cumming-Bruce, David M. Halbfinger, and Fahim Abed contributed reporting.