Data published by the bureau showed that US exports to Iran between January and April were worth $98.2 million, up from $58.7 million during the same period in 2014.
March 2015 contributed the biggest share of total exports, bringing in more than $44 million, compared to less than $19 million in March 2014, Sputnik reported.
The total value of exports in 2014 from the United States to Iran amounted to $186.5 million, which was significantly lower than the over $300 million in US exports to the Islamic Republic in 2013.
Ties between Washington and Tehran are still affected by sanctions imposed on Iran over its nuclear program.
While Iran insists its nuclear program is peaceful and not meant for developing nuclear weapons, the US and other countries have levied sanctions against Tehran over concerns that it is not being truthful.