Obama said there are "different, mixed signals" coming from Iran and "it's not always clear who's speaking on behalf of the government."
"Despite their posturing that their nuclear power is only for civilian use, that they, in fact, continue to pursue a course that would lead to weaponization, and that is not acceptable to the international community, not just to the United States," the president said.
Obama called himself "an eternal optimist" and said he thinks Republicans and Democrats can come together to draft bipartisan comprehensive energy reform.
He said both sides of the coin need to be considered: pushing for development of new, green technologies as well as continued support for what he deemed "old traditional energy sources" to produce jobs and economic growth.
The president said the key question is how to draft an energy package that includes "safe, secure nuclear power," incorporates new technology to continuing using coal and increases oil and gas production in an environmentally sustainable way.
"My hope is that when my Republican friends, but also Democrats, say to themselves, 'Let's be practical, and let's do both, let's not just do one or the other, let's do both,' over time I think the transition is going to be more and more clean energy, and over time fossil fuels become less prominent in our overall energy mix," he said.
At a town hall in Nashua, N.H., last week, Obama said the "controversial" cap and trade mechanism that was approved by the House could be considered separately in the Senate as it develops energy reform legislation.
"We may be able to separate these things out, and it's conceivable that that's where the Senate ends up," he said. "But the concept of incentivizing clean energy so that it's the cheaper, more effective kind of energy, is one that is proven to work and is actually a market-based approach."