Trump: Iran downing of drone might have been unintentional

US President Donald Trump said on Thursday that Iran had made a "very big mistake" by shooting down an unmanned US surveillance drone on Wednesday, but hours later seemingly sought to downplay the Iranian action, saying that he found it "hard to believe" that it "was intentional".

During an Oval Office meeting with Canadian Prime Minster Justin Trudeau, Trump said, "I find it hard to believe it was intentional," adding that it would have made a "big, big difference" if there had been someone inside the drone.

Speaking with reporters at the White House, Trump said the US had "scientifically" documented evidence that the drone was in international airspace. He reiterated his view that endless wars need to end, but he cast the downing of the drone as a new provocation.

"We're pulling a lot of people back but this is a new wrinkle," Trump said, noting decisions to draw down troops in Syria and Afghanistan. "This is a new fly in the ointment, what happened shooting down the drone. And this country will not stand for it, that I can tell you."

Earlier on Thursday, Trump had said "You'll find out" as to whether the US would respond militarily to Iran's downing of the drone that it claimed was in its airspace.  "Obviously, you know, we're not going to be talking too much about it," Trump said about a possible response. "You'll find out. They made a very big mistake."

After a briefing for congressional leaders at the White House late Thursday afternoon, Senate Majority Leader Mitch McConnell said the administration is considering "measured responses". He gave no details.

Senate Minority Leader Chuck Schumer said he spoke to Trump about the Iran drone attack during the briefing for congressional leaders.

"I told the president that these conflicts have a way of escalating. The president may not intend to go to war here, but we're worried that he and the administration may bumble into a war," Schumer told reporters.

"We told the room that the Democratic position is that congressional approval must be required before funding any kind of conflict in Iran. One of the best ways to avoid bumbling into war, a war that nobody wants, is to have a robust, open debate and for Congress to have a real say. We learned that lesson in the run-up to Iraq," Schumer said.

House Speaker Nancy Pelosi, who also attended the meeting, said it is essential the US remain "engaged with our allies".

The US must recognize that "we are not dealing with a responsible adversary and do everything in our power to de-escalate," she said in a statement.

The downing of the drone raises US-Iran tensions amid events of recent weeks, including attacks on energy tankers in the Gulf of Oman — which Iran has been blamed for and denied — and Teheran's warning that it will break internationally agreed upon limits on uranium production. Earlier this week, Trump described attacks on two tankers in the gulf as "very minor" in an interview with Time magazine.

The commander of Iran's Revolutionary Guard said the shooting down of the drone has sent "a clear message" to America. General Hossein Salami also said that Iran does "not have any intention for war with any country, but we are ready for war."

In the Oval Office talking to reporters, Trump said his advisers weren't pushing him into a war with Iran.

"No, not at all. Not at all. In fact, in many cases it's the opposite," he said. "Look, I said I want to get out of these endless wars. I campaigned on that. I want to get out."

Trump has said privately over the past weeks that he is not interested in getting into another foreign conflict. But two of his senior advisers — Secretary of State Mike Pompeo and national security adviser John Bolton — are especially hawkish on Iran and have used tougher language.

US military officials maintained that the drone was shot down in international airspace above the Strait of Hormuz. Lieutenant General Joseph Guastella, commander US Air Forces Central Command, said during a briefing at the Pentagon that Iran's action was "an unprovoked attack" and called Iran's claim that the drone was in Iranian airspace "categorically false".

Guastella briefed reporters remotely from Al Udeid Air Base in Qatar and didn't take any questions.

Iran's foreign affairs minister, Mohammad Javad Zarif, posted a Twitter message on Thursday in which he gave what he said were precise coordinates for where the US drone was targeted, which would put it eight miles off Iran's coast, inside the 12 nautical miles from shore that Iran claims as territorial waters.

"We've retrieved sections of the US military drone in OUR territorial waters where it was shot down,'' he said.

"Despite repeated radio warnings, it entered into the Iranian airspace where the air defense system of the Islamic Republic of Iran, acting under Article 51 of the United Nations Charter, targeted the intruding aircraft," Iran's UN ambassador wrote in a letter to the Security Council. He said that Teheran "does not seek war" but "is determined to vigorously defend its land, sea and air."

UN Secretary General António Guterres appealed to all sides to "exercise maximum restraint", according to his spokesperson.

Russian President Vladimir Putin on Thursday warned the US against using force on Iran.

"It would be a catastrophe, for the region at the very minimum, because it will lead to an increase in violence, and potential increase in refugees from the region," Putin said during a televised call-in show. "But also, for those who would attempt it, it could have possibly sad consequences."

Putin said that Iran is ready to go "to the extremes" to defend itself, and that it's hard to tell where that would lead.

He also said that he is satisfied that Iran has been abiding by its nuclear agreements, and that "the application of sanctions against it are not justified".

The Trump administration pulled out of an international nuclear agreement with Iran last year and re-imposed sanctions on the country.

Iran has recently said it will exceed on June 27 the limit on the amount of uranium it is allowed to stockpile under the international nuclear deal. It has also threatened to increase the level of enrichment of its uranium, bringing it closer to weapons-grade.

Earlier this week, Israeli Prime Mnister Benjamin Netanyahu called on the international community to impose sanctions on Iran if it enriches low-grade uranium beyond the limits allowed in the nuclear deal, which he staunchly opposed.