President Donald Trump told reporters Thursday that Iran may not have intentionally downed an unmanned U.S. surveillance drone. He said the public will “find out” about whether the U.S. intends to retaliate with a military strike.

“I find it hard to believe it was intentional,” Trump said during a White House meeting with Canadian Prime Minister Justin Trudeau.

“I think they made a mistake, and I’m not just talking the country made a mistake. I think that someone under the command of that country made a big mistake,” Trump said.

U.S. stocks briefly dipped to session lows after Trump said “you’ll soon find out” when asked if the U.S. would strike Iran. They resumed their climb with his subsequent comments about Iran’s intentions.