Siluanov would not say whether a deal had been sealed with Iran.

U.S. Treasury Secretary Jack Lew warned Siluanov on Thursday on the sidelines of a International Monetary Fund-World Bank meeting in Washington that any oil-for-goods deal Moscow might strike with Iran could run afoul of U.S. sanctions.

"We act on the basis of the decisions made by the United Nations that set sanctions, set product groups which would be sanctioned and we operate within those decisions," Siluanov told journalists.

"There is a nuance. Our American partners have their own legislation which differs somewhat from the provisions set by the United Nations and they follow their own rules."

(Reporting by Lidia Kelly, editing by Elizabeth Piper)