Obama, speaking at his first press conference since winning Tuesday's presidential election, also confirmed that he had been sent a letter from Iranian President Mahmoud Ahmadinejad following his victory.
"I am aware that the letter was sent," Obama said in response to the only question of the press conference about foreign policy. "I will be reviewing the letter from President Ahmadinejad and we will respond appropriately."
"It has only been three days since the election, and obviously, how we approach and deal with a country like Iran is not something that we should, you know, simply do in a knee-jerk fashion," Obama said. "We have to think it through."
The president-elect called for an "international effort" to stop Iran from developing a nuclear weapon.
"Let me repeat and state what I stated in the course of the campaign," he said. "Iran's development of a nuclear weapon I believe is unacceptable. We have to mount an international effort to prevent that from happening."
Obama added that "Iran's support of terrorist organizations, I think, is something that has to cease."
The president-elect also stressed during the 20-minute press conference that he has not yet taken office and won't until January 20, 2009.
"I have to reiterate once again, we only have one president at a time," he said. "I want to be very careful that we are sending the right signals to the world as a whole."
