The International Energy Agency reported that oil exports from Iran were down from the February level of 1.26 million barrels per day to 1.1 million bpd in March.
Iranian Finance Minister Shamseddin Hosseini told Bloomberg News from U.N. headquarters the government was making adjustments in response to economic pressure on its oil industry.
"We have seen an increase of 20 percent in non-oil exports," he said. "We are making structural changes to our economy to reduce the impact of sanctions."
Iran expects a 40 percent decline in oil revenue for the fiscal year beginning March 21, the start of the Persian year.
Iran's currency collapsed under sanctions pressure last year. The International Monetary Fund said the Iranian economy should contract 1.3 percent this year, after a 1.9 percent decline in 2012.
Sanctions pressure is meant to starve Iran of the money to finance its nuclear program.
Hosseini said, "The development of peaceful civilian nuclear program is one of our highest priorities."