Updated at 3 p.m. ET
Hours after Iran announced that it had shot down a U.S. drone, President Trump told journalists at the White House, "You'll soon find out" if the U.S. is planning a strike on Iran in retaliation.
"They're going to find out they made a very big mistake," Trump added, in comments that came as he met with Canadian Prime Minister Justin Trudeau.
But Trump also said he suspects that Iran's taking out the drone was not intentional, saying he finds it hard to believe.
"I have a feeling that it was a mistake made by somebody that shouldn't have been doing what they did." The president speculated that "it could have been someone loose and stupid."
Trump added that it makes a "big, big difference" that the drone was unmanned.
Iran's Revolutionary Guard said Thursday that it had shot down a U.S. drone over its territory to send "a clear message" to America, but the U.S. military says the unmanned aircraft was operating in international airspace.
The Revolutionary Guard said it downed an RQ-4 Global Hawk surveillance drone that had entered Iranian airspace around Kouhmobarak district in the country's south, near the Gulf of Oman.
"Iranian reports that the aircraft was over Iran are false," U.S. Central Command spokesman Navy Capt. Bill Urban said Thursday morning. "This was an unprovoked attack on a U.S. surveillance asset in international airspace."
In a midday briefing, Lt. Gen. Joseph Guastella, commander of U.S. Air Forces Central Command, clarified the position of the aircraft during an audio link session with reporters at the Defense Department, saying that the drone "had not violated Iranian airspace at any time during its mission."
Guastella said the U.S. drone was flying at high altitude and was 34 kilometers "from the nearest point" to Iran's coast when it was shot down by a surface-to-air missile fired by the Revolutionary Guard. He said the drone was operating in the Gulf of Oman and Strait of Hormuz and fell into international waters.
The general called the Iranian strike dangerous and irresponsible, adding that it occurred "in the vicinity of established air corridors, possibly endangering innocent civilians."
Gen. Hossein Salami, the Revolutionary Guard's commander, was quoted by The Associated Press as saying Iran does "not have any intention for war with any country, but we are ready for war."
Responding to the news of the shootdown, Trump said via Twitter, "Iran made a very big mistake!"
Iranian Foreign Minister Javad Zarif issued a tweet saying his country had "retrieved sections of the US military drone" in its territorial waters "where it was shot down."
At 00:14 US drone took off from UAE in stealth mode & violated Iranian airspace. It was targeted at 04:05 at the coordinates (25°59'43"N 57°02'25"E) near Kouh-e Mobarak.— Javad Zarif (@JZarif) June 20, 2019
We've retrieved sections of the US military drone in OUR territorial waters where it was shot down. pic.twitter.com/pJ34Tysmsg
Sen. Lindsey Graham took a hawkish position as he reacted to the news Thursday. "The only thing Iran and every other thuggish regime understands is strength and pain," he wrote in a statement.
"It is imperative the United States clearly inform the Iranians that any effort to increase uranium enrichment will be seen as a hostile act against the United States and our allies in Israel, and will not go unanswered," he added.
Graham said that any military response "should be focused on Iranian naval capabilities and the oil refineries which are the economic lifeblood of this murderous regime."
U.S. Central Command says Iran used a surface-to-air missile system to shoot down the U.S. Navy Broad Area Maritime Surveillance ISR (intelligence, surveillance and reconnaissance) aircraft. It says the drone was operating in international airspace over the Strait of Hormuz when it came under fire at approximately 11:35 p.m. GMT late Wednesday.
According to Urban, the downed drone is an RQ-4A Global Hawk, the Navy's version of the high-altitude, long-endurance aircraft that performs intelligence and surveillance missions "over vast ocean and coastal regions."
Earlier this week, the Pentagon said Iran had attempted to shoot down a U.S. drone. It also acknowledged the shooting down of an MQ-9 Reaper drone on June 6 by Yemen's Houthi forces, which are allied with Iran. The U.S. said Iran helped the Houthis bring down the pilotless aircraft.
Military.com describes the Global Hawk as an unarmed craft used for intelligence-gathering missions. The vehicle reportedly has a top speed of nearly 355 mph and a range of 10,000 miles.
The area where Iran says the drone went down is near where the U.S. claims Iran attacked two oil tankers last week. Iran has repeatedly denied being involved in that attack.
IRGC-affiliated FarsNews says the IRGC has shot down a US surveillance drone, RQ-4 Goobal Hawk, when it was "flying over Iran southern sealines" In the Persian Gulf. https://t.co/iWbCsHvFwx pic.twitter.com/pCSZ0TBWmH— Hadi Nili (@HadiNili) June 20, 2019
The attack on the drone comes at a time of heightened tensions between the U.S. and Iran, not only with the alleged attacks on the tankers but with Iran threatening to step up its nuclear activities and the U.S. working to exert maximum pressure through economic punishments.
Last year, the Trump administration reimposed sanctions on Tehran after abruptly withdrawing from the 2015 multinational agreement to limit Iran's nuclear program.
Despite Washington's withdrawal, the Joint Comprehensive Plan of Action technically remains in force with the other signatories — Iran, the four non-U.S. permanent members of the U.N. Security Council and the European Union.
However, this week a spokesman for Iran's atomic energy agency warned that Tehran would surpass limits on its uranium stockpile under the deal and said it was prepared to increase its enrichment to a level just one step short of weapons grade, which also violates the terms of the agreement.
Also, Houthi rebels in Yemen on Wednesday said they hit a Saudi power station with a cruise missile. White House press secretary Sarah Sanders said Trump had been "briefed on the reports of a missile strike in the Kingdom of Saudi Arabia."
"We are closely monitoring the situation and continuing to consult with our partners and allies," Sanders added.