U.S. President-elect Barack Obama has said Iran’s development of a nuclear weapon is ‘unacceptable’. At his first news conference since Tuesday’s victory, Barack Obama also said Tehran must stop its “support of terrorist organisations”.

Speaking to some 400 members of the media who gathered at the Chicago Hilton, Obama said:  

“Iran's development of a nuclear weapon I believe is unacceptable. And we have to mount an international effort to prevent that from happening. Iran's support of terrorist organisations I think is something that has to cease.”

On Thursday, Iranian President Mahmoud Ahmadinejad sent his congratulatory letter to Obama on his win over Republican John McCain. It’s the first time since the 1979 Islamic Revolution that the head of the republic sent his wishes to an American leader. Obama said he would be reviewing the letter from President Ahmadinejad, and “we will respond appropriately”.

“It's only been three days since the election. 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. I think we've got to think it through,” he added.

During his 20-minute conference, Obama underlined that he hasn’t yet been sworn in as the President of the U.S.

“ I have to reiterate once again that we only have one president at a time. And I want to be very careful that we are sending the right signals to the world as a whole that I am not the president and I won't be until January 20th,” Obama said.

Not surprisingly, the financial crisis was the main topic the President-elect spoke about.

“Tens of millions of families are struggling to figure out how to pay the bills and stay in their homes. Their stories are an urgent reminder that we are facing the greatest economic challenge of our lifetime, and we're going to have to act swiftly to resolve it.”

He promised that immediately after he becomes President, he’s going “to confront this economic crisis head on by taking all necessary steps to ease the credit crisis, help hardworking families, and restore growth and prosperity.”

He spoke briefly about key priorities his team will focus on in the coming weeks.

“I do not underestimate the enormity of the task that lies ahead. We have taken some major action to date, and we will need further action during this transition and subsequent months. Some of the choices that we make are going to be difficult. And I have said before and I will repeat again: It is not going to be quick, and it is not going to be easy for us to dig ourselves out of the hole that we are in,” Obama said.

This highly anticipated media briefing, however, left journalists a little bit disappointed because of the lack of information that they got.

Obama kept quiet about many important issues such as his future foreign policy, didn’t give many details about how exactly he is going to tackle financial crisis, and didn’t make any new announcements about appointments to his administration.