President Donald Trump declared Thursday that "Iran made a very big mistake" in shooting down a U.S. drone but suggested it was an accident rather than a strategic error.
Asked about a U.S. response, he said repeatedly, "You'll find out."
Earlier, a senior U.S. military officer said Iran shot down the huge, unmanned American aircraft over international waters in an attempt to disrupt U.S. efforts to monitor the Persian Gulf area where Trump has blamed Iran for attacking shipping vessels.
But Trump said he could not imagine the missile attack on the drone was intentional and he had a feeling "a general or somebody" mistakenly ordered the attack.
Some members of Congress expressed alarm at the possibility of open conflict in the Middle East, especially after Trump's morning tweet that said only, "Iran made a very big mistake."
But when asked about it later, he merely described the incident as a "new wrinkle" in escalating tensions between the U.S. and Iran - a "fly in the ointment."
Still he said the U.S. "will not stand for it."
Top congressional leaders were called to the White House for a briefing later on Thursday on Iran following the downing of a U.S. surveillance drone, a source with knowledge of the meeting said.
The meeting, with the top four leaders of the U.S. Congress as well as heads of the U.S. Congress Armed Services and Intelligence committees, was to be held in the White House Situation Room
Shortly before Trump spoke at to reporters at a photo opportunity with visiting Canadian Prime Minister Justin Trudeau, Air Force Lt. Gen. Joseph Guastella, commander of U.S. Central Command air forces in the region, took a different tack from Trump's idea of an accidental shootdown.
Prime Minister Benjamin Netanyahu in a statement Thursday called for all peace-loving countries to stand by the United States in its effort to stop Iran's aggression.
"This attack is an attempt to disrupt our ability to monitor the area following recent threats to international shipping and free flow of commerce," he said.