President Barack Obama is warning Iran that the window for dealing with its nuclear program through diplomatic channels is "shrinking."
Obama says he still prefers to use diplomacy to get Iran to abandon its nuclear program. But he says diplomacy requires having somebody on the other side of the table who is taking the matter seriously.
The president says he hopes Iran understands that diplomacy is their "best bet" and the Islamic regime needs to seize that opportunity. Iran insists its nuclear program is for peaceful purposes and says it is not seeking a bomb.
Obama is speaking at a White House news conference alongside British Prime Minister David Cameron.