"There is no sense behind talk of the severing of relations... They express their desire to invest in Russia," Novak told reporters when asked if sanctions had hit energy cooperation.
The world's top crude oil producer and a leader in natural gas, Russia has signed deals with international majors on developing energy resources, mainly in the offshore Arctic region.
Top Russian oil firm Rosneft has signed agreements with ExxonMobil, Eni and Statoil (STO)
and its biggest shareholder after the state is London-based BP (BP)
BP boss Bob Dudley said this week that Western sanctions over Russia's actions in Ukraine had not impacted the company's business in Russia.
Ben van Beurden, the new boss of Royal Dutch Shell (RYDAF)
, which holds a stake in Russia's only liquefied natural gas producing plant, is scheduled to meet Russian President
Vladimir Putin on Friday in a sign of the company's commitment to its business in the country.
"The project is being implemented on the basis of agreements between the countries. According to international law, these agreements cannot be suspended. We have been in consultations with the European Commission over South Stream, the work is going on," Novak said.
Doubts have been raised about the future of the project since Russia's annexation of Ukraine's Crimea region, a move that has angered both the EU and Washington.
The EU's approvals process regarding South Stream has been put on hold, European Commissioner for Energy Guenther Oettinger said.
Hoping to build the pipeline is a consortium including Russian gas exporter Gazprom as well as European partners Wintershall, Eni and EDF.
South Stream is designed to carry more than 63 billion cubic metres of gas to Europe a year by the end of the decade, meeting up to 15 percent of Europe's needs.
(By Anastasia Lyrchikova, writing by Vladimir Soldatkin; editing by Alessandra Prentice and Jason Neely)