US President Donald Trump on Thursday suggested that the shooting down of a US surveillance drone by Iran may have been a mistake.
In comments that appeared to downplay the shooting despite soaring tensions in the Strait of Hormuz area, Trump while speaking to reporters in the Oval Office claimed that the drone had been unarmed and in international waters, and that it could have been shot down by someone who was "loose and stupid".
"I think probably Iran made a mistake ─ I would imagine it was a general or somebody that made a mistake in shooting that drone down," Trump said during an appearance with Canadian Prime Minister Justin Trudeau.
"I find it hard to believe it was intentional," Trump said. "I have a feeling that it was a mistake made by somebody who should not have been doing [that]."
"This country will not stand for it, that I can tell you," he added.
Asked how the US would respond to Iran after the downing of the drone, Trump told reporters, "You'll find out."
Trudeau said he was very concerned about escalations in tensions with Iran.
Iran's Revolutionary Guard said that it had brought down the unmanned surveillance aircraft as it was "violating Iranian air space" over the waters of Hormozgan province.
The Pentagon, however, denounced the "unprovoked attack" in international air space, claiming the drone was some 34 kilometres from the nearest point in Iran when it was downed by a surface-to-air missile.
Iran vowed in response to go to the United Nations to prove Washington was "lying".
Crude oil prices rose more than 6 per cent after the incident which marked a new peak in tensions as Tehran pushes back against surging US diplomatic, economic and military pressure.
Trump has repeatedly said he does not favour war with Iran unless it is to stop the country getting a nuclear weapon ─ something Iranian leaders insist they are not pursuing ─ yet members of Congress reacted quickly with that possibility as background.
Critics of the Trump administration also say that his policy of "maximum pressure" ─ including crippling economic sanctions, abandonment of a complex international deal to regulate Iran's nuclear activities, and deployment of extra sea, air and land forces to the region ─ make war ever more likely.
The Senate's top Democrat called the downing of the American drone "deeply concerning" and accused the administration of not having an Iran strategy and keeping Congress and the American people in the dark.
"The president needs to explain to the American people why he's driving us toward another endless conflict in the Middle East," said Sen. Chuck Schumer of New York.
House Speaker Nancy Pelosi said she doesn't think Trump wants war with Iran and the American people have "no appetite" for it either.
She said the US needs to be "strong and strategic" about protecting its interests and "cannot be reckless".
Talking tougher, Republican Sen. Lindsey Graham of South Carolina called Iran a "murderous regime" and blamed Tehran for the current tension.
Graham, who spoke with Trump by telephone on Thursday morning, claimed that the Iranians had rebuffed the president's willingness to negotiate by refusing to respond to a letter from Trump that Japanese Prime Minister Shinzo Abe recently hand-delivered.
"Not only did the Iranians give a provocative oral response, but they also attacked a Japanese oil tanker at the same time," Graham alleged, referring to the attack on Kokuka Courageous, a Japanese tanker carrying Saudi methanol that was travelling in the Gulf of Oman. Iran has denied involvement.
As for the possibility of Iran developing nuclear weapons, Graham said it is imperative that the US clearly tell the Iranians that any attempt 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."
Graham added that if a US military response is necessary, it should be focused on Iranian naval assets and oil refineries, which are the economic lifeblood of the country.
'Disaster for region'
Russian President Vladimir Putin said that US military retaliation against Iran "would be a disaster for the region."
Israeli Prime Minister Benjamin Netanyahu appealed to "all peace-loving countries" to support American efforts to halt what he called escalating Iranian provocations.
Speaking on Thursday at a reception for the New England Patriots owner Robert Kraft, Netanyahu said that "in the last 24 hours, Iran has intensified its aggression against the United States and against all of us," adding that "Israel stands by the United States on this."
Israeli officials have welcomed Washington's mounting pressure on Tehran, but steered clear of calling for a conflagration that might put Israel in the line of fire.