Iran says it has enhanced its capability to enrich uranium.
The announcement sparked quick condemnation from the United States and Europe. But it is not clear just how significant a step it is.
With an atomic symbol superimposed over an Iranian flag as his backdrop, President Mahmoud Ahmadinejad announced Iran is capable of enriching uranium on, what he termed, an industrial-level.
But in his announcement, made at the Natanz nuclear facility in central Iran, he did not define "industrial-level."
Matthew Bunn, senior researcher at the Managing the Atom Project at Harvard University, says although the statement was vague, the announcement was a clear snub to the UN Security Council, which has demanded Iran halt uranium enrichment."
"It is a clear statement of resistance to the Security Council legal requirement that Iran suspend all enrichment activities. It is a clear statement that they are not going to do that, they are going to move ahead at full speed. What we do not know is how far they have come and how fast they will move forward from here."
The announcement brought swift condemnation from the United States and its European allies.
State Department spokesman Sean McCormack called it a lost opportunity for Iran to halt its nuclear work and enter negotiations. He said Iran has a credibility problem.
"The problem is with the behavior of the Iranian regime in answering the international system's legitimate questions about its nuclear program. And quite frankly, we have gotten to the point, now, in the international community where the members of that international community, including the Security Council and the IAEA board of governors do not believe Iranian assurances that their program is peaceful in nature."
The Security Council has imposed limited sanctions on Iran for its nuclear activity.
The Security Council and Germany believe Iran is determined to acquire a nuclear weapons capability.
Iran denies the charge, saying it is only working to build peaceful nuclear energy for power generation.
Iran has announced a goal of installing three-thousand centrifuges at the Natanz plant.
The centrifuges spin at supersonic speed to enrich fuel for nuclear reactors. If Iran has three-thousand operating centrifuges, analysts say it would be a significant step towards building a nuclear bomb.
But Paul Kerr, an analyst at the Arms Control Association, says there is reason to believe Iran's claims of nuclear prowess are exaggerated.
He says Iran is believed to currently have only one-thousand operational centrifuges.
"I would say the diplomatic consequences of this are clearer than the technical consequences. And we are just going to have to wait to get some more detail both from the IAEA and from the Iranians. I think some of their officials, at least in the past, have provided some details about what is going on. So we are really just going to have to wait."
The IAEA, or International Atomic Energy Agency, is due to deliver another report on Iran's nuclear program to the UN Security Council in late May.