President Donald Trump has said “Iran made a very big mistake” in shooting down a US drone, increasing tensions and talk of possible open conflict.
Iran has been blamed by the US for recent attacks on other nations’ shipping vessels, but the downing of the huge drone was the first direct Iranian assault against the United States.
American and Iranian officials are disputing the circumstances of the incident.
Iran’s Revolutionary Guard said it shot the drone down over Iranian airspace.
The US military is calling the downing an “unprovoked attack” and said it occurred over international airspace in the Strait of Hormuz.
“Iran made a very big mistake!” Trump tweeted.
Trump has said repeatedly that the US does not want war in the Middle East, yet members of Congress reacted quickly with that possibility in the background.
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,” Senator Chuck Schumer said.
House Speaker Nancy Pelosi said she did not think Trump wanted war with Iran and the American people had “no appetite” for it either.
She said the US needed to be “strong and strategic” about protecting its interests and “cannot be reckless”.
Republican Senator Lindsey Graham called Iran a “murderous regime” and blamed Tehran for the current tension.
Graham, who spoke with Mr Trump by telephone on Thursday morning, said the Iranians had rebuffed the president’s willingness to negotiate by refusing to respond to a letter from Trump recently hand-delivered by Japanese prime minister Shinzo Abe.
As for the possibility of Iran developing nuclear weapons, Graham said it was imperative that the US clearly told the Iranians that any attempt to increase uranium enrichment would be seen as a “hostile act against the United States and our allies in Israel and will not go unanswered”.
Mr Graham added that if a US military response was necessary, it should be focused on Iranian naval assets and oil refineries, which were the economic lifeblood of the country.
Iran has quadrupled its production of low-enriched uranium and threatened to boost its enrichment closer to weapons-grade levels, trying to pressure Europe for new terms to the 2015 nuclear deal that Iran struck with the US and other world powers.
In recent weeks, the US has sent an aircraft carrier to the Middle East and deployed additional troops alongside the tens of thousands already in the region.