WASHINGTON – The rising tensions between the United States and Iran continued on Thursday morning, when a U.S. surveillance drone was shot down by Iran's Revolutionary Guard in what a U.S. official called an "unprovoked attack."
U.S. and Iranian officials gave differing accounts of the attack, which comes as the war of words between the U.S. and Iran threatens to spill into open conflict.
Here's what we know so far about the drone attack and the tensions between the U.S. and Iran:
What the U.S. is saying
The key difference between the two sides is that U.S. officials said the drone was shot down in "international airspace" over the Strait of Hormuz.
In a briefing at the Pentagon on Thursday, Lt. Gen. Joseph Guastella, commander of U.S. Air Forces Central Command, called into the Pentagon from a base in Qatar:
"A U.S. Navy RQ-4 was flying over the Gulf of Oman and the Strait of Hormuz on a surveillance mission in international airspace in the vicinity of recent IRGC maritime attacks when it was shot down by an IRGC surface to air missile fired from a location in the vicinity of Goruk, Iran," Guastella said.
"This was an unprovoked attack on a U.S. surveillance asset that had not violated Iranian airspace at any time during its mission," he continued. "This attack is an attempt to disrupt our ability to monitor the area following recent threats to international shipping and free flow of commerce."
Guastella reiterated that Iranian claims that the drone was shot down over Iranian airspace "categorically false."
Trump discussed the issue during an Oval Office meeting later on Thursday, saying, "Iran made a big mistake. This drone was in international waters, clearly. We have it all documented scientifically not just words. And they made a very bad mistake."
When asked about how the U.S. would respond, he said, "you'll find out."
Trump added that he thought it was someone "loose and stupid who did it."
What Iran is saying
Iran has alleged that the drone had violated Iranian airspace, saying the drone fell in the Kouh-e Mobarak region in the central district of Jask.
Iran and the U.S.: Escalating Iran crisis looks a lot like the path US took to Iraq war
Major General Hossein Salami, a spokesperson for the Iranian Revolutionary Guard, said the incident serves as a warning to the U.S.
"The downing of the U.S. drone had an explicit, decisive and clear message that defenders of the Islamic Iran’s borders will show decisive and knockout reactions to aggression against this territory,” Salami said at a news conference in Kurdistan Province. “Borders are our redline, and any enemy violating these borders will not go back."
Iran's drone takedown comes a week after two oil tankers were attacked in the Gulf of Oman.
The Trump administration has said that Iran is responsible for those attacks, although Iran has denied responsibility. Since then, the U.S. military has released video and photographs claiming to show a relationship between Iranian forces and the attacks on the tankers.
Despite previous comments by top Trump administration advisors on the threat posed by Iran, President Donald Trump has contradicted his top advisors. In an interview with TIME posted this week, Trump said that the attacks were "very minor."
The U.S. has also deployed more troops to the Middle East in what Pentagon officials say is a direct response to Iran's provocations.
On Monday, acting Defense Secretary Patrick Shanahan announced that 1,000 troops would be sent to the Middle East "to address air, naval, and ground-based threats in the Middle East." Shanahan cited "hostile behavior by Iranian forces and their proxy groups that threaten United States personnel and interests across the region."
Iran announced this week that it would soon be breaking its nuclear stockpile and enrichment limits set under the 2015 Joint Comprehensive Plan of Action, also known as the "Iran Deal." The U.S. withdrew from that pact in 2015, but the U.S. has urged Iran to abide by its provisions.
In a television interview last Sunday on Fox News, Pompeo restated America's goals regarding Iran's nuclear program.
"President Trump has been unambiguous: Iran will not get a nuclear weapon," he said. "That's the goal, that’s the objective of our entire campaign with respect to Iran and to create stability throughout the Middle East as part of that effort."
Does this look like the buildup to the Iraq War?
The saber-rattling between the U.S. and Iran appears to have parallels to the build-up to the 2003 Iraq War.
On Wednesday, the New York Times reported that the Trump administration was trying to make the case to Congress that Iran had ties to Al Qaeda, which under a 2001 congressional authorization, would potentially give the Trump administration the legal authority to take military action against Iran.
Pompeo ducked a question about military authorization during a Fox News interview last Sunday, saying that “the president has the authorization to act to defend American interests," but did not elaborate on what authorization that was.
A Reuters/Ipsos poll released in late May shows that half of all Americans believe the U.S. will go to war with Iran "within the next few years."
Contributing: Michael Collins, John Bacon, Rebecca Morin and Kim Hjelmgaard
This article originally appeared on USA TODAY: Iran shoots down US drone: What Iran and the United States are saying