Holder said Manssor Arbabsiar and Gholam Shakuri were charged with conspiracy to murder a foreign official, conspiracy to use a weapon of mass destruction and conspiracy to commit an act of international terrorism among other charges.
"In addition to holding these individual conspirators accountable for their alleged role in this plot, the United States is committed to holding Iran accountable for its actions," he added.
Arbabsiar has been in custody since Sept. 29, 2011 and Shakuri remains at-large according to Holder.
"The disruption of this alleged plot marks a significant achievement by our law enforcement and intelligence agencies as well as our close cooperation of our partners in the Mexican government, he said.
For the latest on Holder's announcement on The Hill's Briefing Room blog, click here.