"Even if U.S. President Barack Obama dares to repeat threats of tougher sanction against us as much as 10 times, we will still be determined to pursue our enrichment program, but with a much faster pace," Iranian Parliament Speaker Ali Larijani said Thursday in remarks published by the semi-official Fars News Agency.
Tensions over Iran's nuclear ambitions grew with last week's announcement by Iranian President Mahmoud Ahmadinejad that uranium enrichment would be stepped up.
At celebrations of the 31st anniversary of the Islamic Republic Thursday, Ahmadinejad declared the first batch had been processed and reiterated that Iran was now a "nuclear state."
White House Press Secretary Robert Gibbs said he doubts Iran has achieved the figures they are claiming.
"We do not believe they have the capability to enrich to the degree they say they are enriching," he said.
In an Islamic Republic News Agency reported by Iran's state-supported Press TV, Iranian Ambassador to the United Nations Mohammad Khazaee said the huge turnout of supporters for the anniversary celebrations shows the strength of the country's will "in the realization of political, economic and social developments and particularly in advancing civilian nuclear technology."