Russian Energy Minister Alexander Novak has said Moscow will support Iran to counter US oil sanctions.
Washington on Friday restored sanctions on Tehran, which had previously been lifted under the 2015 nuclear deal.
The measures are due to come into effect on Monday.
In an interview with the British Financial Times newspaper, Novak said that Russia is looking to continue trading Iranian crude oil beyond the Monday cut-off.
"We believe we should look for mechanisms that would allow us to continue developing cooperation with our partners, with Iran," Novak told the FT.
Under a 2014 oil-for-goods deal, Moscow sells Iranian oil to third parties while Tehran uses the revenues from those sales to pay for Russian goods and services.
The Russian energy ministry told the FT that the trade would continue next week, while Novak said that Moscow considered the US sanctions to be "illegal".