[1] He has said this before.

From [2] YnetNews:

Iran is now a "nuclear power," its President, Mahmoud Ahamdinejad, declared Wednesday, according to the Islamic Republic News Agency. During a speech delivered in the Western Iranian province of Javanroud, Ahmadinejad said: " The Islamic Republic of Iran is now a nuclear power, thanks to the hard work of the Iranian people and authorities."

The announcement of Iran as a "nuclear power" is bound to significantly escalate tensions between the West and Iran, and marks a dramatic stage in the Islamic Republic's nuclear campaign.

In recent days, the US military has begun to build up forces around the Gulf, in what is being seen as as a warning to Iran.