President Donald Trump said Thursday that Iran has made a "very big mistake" by shooting down a US spy drone, an incident that is likely to further escalate already soaring tensions between Washington and Tehran.
Both the US and Iran said that Iranian forces had shot down an American military surveillance drone, but the two sides offered conflicting details on the incident.
"This drone was in international waters, clearly. We have it all documented scientifically not just words. And they made a very big mistake," Trump told reporters in the Oval Office of the White House in a joint media appearance with the visiting Canadian Prime Minister Justin Trudeau.
"Iran made a very big mistake!", President Trump also tweeted soon after the Department of Defence claimed that one of its drones were shot down by the authoritarian Iranian regime.
Asked how he will respond to the alleged Iranian action, Trump said: "You will find out".
Responding to a question, Trump refuted that his advisors were pushing him to a war with Iran.
"No no not at all. In fact in many cases it's the opposite," he said.
"We beat the Caliphate. We took back the 100 per cent of the Caliphate. At 99 per cent, Justin, I said we're going to get out we're going to start peeling back and everybody went crazy because it was 99, and so I said all right, so we'll finish it up. So we got 100 per cent. And we're pulling that back out of Syria. We're pulling a lot of people back," he said.
"But this is a new wrinkle, a new fly in the ointment what happened, shooting down a drone. And this country will not stand for it, that I can tell you," Trump said on the alleged shooting down of American drone by Iran.
US officials confirmed that a high altitude drone on a surveillance mission over the Strait of Hormuz was hit by an Iranian surface-to-air missile in international airspace.
Iran, however, said its elite Revolutionary Guard shot down an RQ-4 Global Hawk drone as it flew over southern Iran and that the incident sent a "clear message to America".
"This was an unprovoked attack on a US surveillance asset that had not violated Iranian airspace at any time during its mission. This attack is an attempt to disrupt our ability to monitor the area following recent threats to international shipping and free flow of commerce," said Lt Gen Joseph Guastella, Commander, US Air Forces Central Command.
"Iranian reports that this aircraft was shot down over Iran are categorically false. The aircraft was over the Strait of Hormuz and fell into international waters. At the time of the intercept, the RQ-4 was operating at high-altitude approximately 34 kilometers from the nearest point of land on the Iranian coast," he said in a statement.
This dangerous and escalatory attack was irresponsible and occurred in the vicinity of established air corridors between Dubai, the UAE, and Muscat, possibly endangering innocent civilians, Guastella said.
The US military's Central Command confirmed a US Navy Broad Area Maritime Surveillance (BAMS-D) aircraft was shot down by an Iranian surface-to-air missile system.
The BAMS-D is a RQ-4A Global Hawk High-Altitude, Long, Endurance (HALE) drone that can carry out surveillance and reconnaissance missions over vast ocean and coastal regions, according to the US military.
Iran's Foreign Ministry issued a condemnation of the purported violation of its airspace and warned of a strong reaction to what it called a "provocative" act by the US.
White House press secretary Sarah Sanders said Trump was briefed Wednesday night and again Thursday morning about the incident.
The incident comes at a time of escalating tension between the two countries.
In the Oval Office, the visiting Canadian Prime Minister expressed his concern over shooting down of the US drone.
"Obviously we are very concerned about the escalation by Iran recently because we have a significant presence in the area, including a NATO mission in Baghdad and Iraq," Trudeau said.
The White House has convened a situation room meeting with eminent members of the Congress on the latest development.
On Monday, the US defence department said it was deploying 1,000 extra troops to the region in response to "hostile behaviour" by Iranian forces. It has already sent an aircraft carrier strike group and B-52 bombers.
The US has also accused Iran of attacking two oil tankers with mines last Thursday just outside the Strait of Hormuz, in the Gulf of Oman. Iran rejects the allegation.
It was the second time in a month tankers had been attacked close in the region, through which a fifth of the world's oil passes each day.
Tensions were further fuelled on Monday when Iran announced its stockpile of low-enriched uranium would next week exceed limits it agreed with world powers under a landmark nuclear deal in 2015.