At a news conference Tuesday, Ahmadinejad said the quickly eroding strength of the rial was part of a "psychological war" the United States and others were waging against Iran to pressure the country to cease work on an alleged nuclear weapons program.
The rial hit a new low at 37,000 to the dollar Tuesday, down from 26,900 just five days ago, the Los Angeles Times reported.
Ahmadinejad said, "the enemy has thrown a rock on our path. Everyone needs to help throw the rock back to the enemy."
The dollar index slid marginally in New York, dropping 0.1 percent to 79.73 on the International Exchange.
Gold for December delivery gave up $5.80 on the Comex division of the New York Mercantile Exchange, sliding off a seven-month high to reach $1,777.50 per troy ounce. Silver shed 29 cents to reach $34.66 per troy ounce.
A troy ounce is 0.083 pound, instead of the standard ounce, which is 0.0625 pound.
The euro rose to $1.2918 from Monday's $1.2888. Against the yen, the dollar rose to 78.16 yen from 78.02 yen.
The British pound rose to $1.6134 from $1.6131. The Australian dollar fell to $1.0264 from Monday's $1.0367.
The dollar rose to 0.9838 Canadian dollars from 0.9824 Canadian. The dollar also rose to 7.7549 Hong Kong dollars from 7.7545 HKD.