U.S. Secretary of State Mike Pompeo has, for the first time, officially confirmed Washington's belief that an Iranian surface-to-air missile shot down the Ukrainian passenger plane that crashed on Wednesday in Iran. 
 
Announcing additional sanctions on Tehran on Friday in a joint news conference at the White House with the Treasury Secretary, Pompeo said it's likely the plane was shot down by an Iranian missile.
 
He said when investigation results are out, he is confident the U.S. and the world will take appropriate actions in response.
 
It's the first time a ranking U.S. official has specifically mentioned Iran related to the plane crash.
 
But Pompeo stopped short of giving evidence to back his statement.
 
Earlier President Donald Trump, without calling out Iran, said that "somebody could have made a mistake" and rejected Tehran's claim of mechanical failure.
 
Iran has initially denied the charges but once a footage of a missile hitting the plane was released, it said it will allow experts of related countries as well as from Boeing and the U.S. National Transportation Safety Board to take part in the investigation.