The United States is likely to take military action against Iran in the coming days for Tehran's downing a U.S. drone in international airspace on Wednesday near the Strait of Hormuz.

The Central Command said an RQ-4 Global Hawk drone aircraft was shot down by an Iranian surface-to-air missile system while operating in international airspace around 7:35 p.m. on Wednesday.

President Trump suggested retaliation for the attack is coming. "Iran made a very big mistake," the president tweeted.

Later during an Oval Office meeting with Canadian prime minister Justin Trudeau, Trump was asked about a military strike against Iran and repeated that Iran "made a very big mistake" because the drone was flying over international waters.

"Iran made a big mistake. This drone was in international waters, clearly," he said. "We have it all documented scientifically, not just words. And they made a very bad mistake."

Trump suggested that the drone was mistakenly shot down and noted that "I have a big, big feeling" an Iranian air defense operator erred in attacking the drone, someone "loose and stupid who did it."

Asked what will come next, the president said "You'll find out."

Air Force Lt. Gen. Joseph Guastella, commander of Central Command air forces, said the RQ-4 drone was conducting surveillance over the Gulf of Oman and the Strait of Hormuz in international airspace near recent IRGC attacks on two tankers. The drone was struck by an IRGC surface-to-air missile fired from a base near Goruk, Iran, he said.

"This was an unprovoked attack on a U.S. surveillance asset that had not violated Iranian airspace at any time during its mission," Guastella said in a statement. "This attack is an attempt to disrupt our ability to monitor the area following recent threats to international shipping and free flow of commerce."

The three-star general also said that Iran falsely claimed the aircraft was shot down over Iran. "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. "This dangerous and escalatory attack was irresponsible and occurred in the vicinity of established air corridors between Dubai, UAE, and Muscat Oman, possibly endangering innocent civilians."

"Iranian reports that the aircraft was over Iran are false," said CENTCOM spokesman Capt. Bill Urban. "This was an unprovoked attack on a U.S. surveillance asset in international airspace."

Tensions have increased with Iran since last week when the Islamic Revolutionary Guards Corps, Tehran's shock troops, were caught removing a limpet mine from the hull of a Japanese tanker that had been hit by other mines the United States has concluded came from Iran.

Another tanker also was attacked with the magnetic mines last week.

Several earlier Iran-linked attacks were carried out, including mines on the ships, an attack on a Saudi pipeline, a rocket firing near a U.S. embassy, and an attack on a NATO convoy in Afghanistan.

White House National Security Adviser John Bolton said in an interview last week the United States is set to retaliate for Iranian military provocations.

"The National Security Strategy lists Iran as one of the four top threats and we just need to be sure we've got the capability to deter them from these kinds of activities, threatening American lives and facilities, threatening the international oil market," Bolton said when asked about the Pentagon's plan to dispatch around 1,000 additional troops to the region.

"They would be making a big mistake if they doubted the president's resolve on this," Bolton added, echoing the president's tweet.

The latest confrontation sent crude oil prices higher over concerns of a new Middle East war. Oil prices increased more than $3 to $63 a barrel, Reuters reports.

U.S. national security officials have been debating how to respond to the recent Iranian military attacks carried out through proxies in a bid to avoid a head-on conflict with the United States.

Options are expected to range from covert action against Iranian military targets using special forces commandos to airstrikes against Iranian bases.

The administration is weighing what it regards as proportional responses to recent Iranian actions.

That would likely mean an airstrike against Iranian air defense batteries located near the Strait of Hormuz that were involved in shooting down the Global Hawk drone.

The launch point of the surface-to-air missile firing, Goruk, is about 100 miles from Iran's Bandar Abbas naval base and the range indicates the missile may have been one of Iran's S-300 advanced air defense missiles. The S-300 has a range of up to 120 miles.

The Goruk facility and Bandar Abbas both could be targeted in a U.S. retaliatory strike.

The Pentagon last month deployed the aircraft carrier strike group led by the USS Abraham Lincoln to the Persian Gulf, along with a bomber strike group of B-52 bombers.

These forces likely would be called on to carry out any future retaliatory strikes.

The IRGC said in a statement that the drone was launched from a U.S. base located in the southern area of the Persian Gulf and flew from the Strait of Hormuz to Chabahar "with complete secrecy."

"The unmanned aircraft while returning to the west of the region towards the Strait of Hormuz, violated the territorial integrity of the Islamic Republic of Iran, and start collecting information and spying," the statement said. "At 4:55 am, when the aggressive UAV entered our country’s territory, it was targeted by the IRGC air force and was shot down."

Iranian state-run media also published a fake picture of a drone being shot down. The drone photo was actually an image of a U.S. drone that was shot down over Yemen in 2017.

Iranian foreign minister Mohammad Javad Zarif said the United States violated Iranian airspace.

"The US wages #EconomicTerrorism on Iran, has conducted covert action against us & now encroaches on our territory," Zarif said on Twitter. "We don't seek war, but will zealously defend our skies, land & waters."

The official IRNA news agency said the drone was shot down near the Mubarak Mountain region in Hormuzgan province in the southern part of the country.

In Saudi Arabia, Adel al-Jubeir, minister of state for foreign affairs, said Iran had created a grave situation through its "aggressive behavior." He said the government there would consult with other states in the region on how to respond.

"When you interfere with international shipping it has an impact on the supply of energy, it has an impact on the price of oil which has an impact on the world economy. It essentially affects almost every person on the globe," al-Jubeir told reporters in London.

Iran earlier threatened to exceed the limits placed on uranium enrichment in response to the Trump administration jettisoning the 2015 nuclear deal.

Bolton said last week that Iran is ramping up uranium production.

"There's no doubt in the minds of IAEA that uranium enrichment has increased, it's not just the more sophisticated centrifuges, but the pace of production, the pace of enrichment has picked up," Bolton said. "And so it threatens the various limits in the JCPOA that the Iranians have said they'll violate, they'll exceed beginning July the 8th."

One model for a U.S. retaliatory strike could be the Reagan administration's Operation Nimble Archer in 1987. American naval forces attacked two Iranian oil platforms in the Persian Gulf in response to an Iranian missile attack on an oil tanker.