Russian Foreign Minister Sergei Lavrov says Russia and Serbia have confirmed their commitment to the South Stream pipeline project.
Lavrov was speaking after talks with Serbian Foreign Minister Ivica Dacic in Belgrade on June 17.
Lavrov said South Stream is the only realistic project that guarantees gas security in southeastern Europe.
He said he is convinced that the suspension of the project is only temporary.
Lavrov added that Moscow expects Serbia to begin building its portion of the pipeline as scheduled in July.
Dacic, who is also Serbia's deputy prime minister, said it was in the Balkan country's "national interest for South Stream to be built."
The multibillion-dollar South Stream project -- led by Russia's state-controlled Gazprom -- is meant to carry Russian gas to the European Union via the Black Sea and through the Balkans, bypassing Ukraine.
Doubts about the project have arisen since Bulgaria announced earlier in June that it is suspending construction of its portion of the pipeline after the European Union said it might be breaking EU rules.
Lavrov's talks in Serbia come after Gazprom cut off gas supplies to Ukraine on June 16 after EU-mediated talks failed to resolve a price dispute.
Ukraine's Prime Minister Arseniy Yatsenyuk called the measure "another stage of Russia's aggression against the Ukrainian state."
The gas-pricing dispute comes with Ukrainian government forces engaged in fighting pro-Russian separatists in eastern Ukraine.
Gazprom also said it has filed a lawsuit in a Stockholm arbitration court to recover what it says are $4.5 billion in unpaid bills from Ukraine.
Kyiv has responded by filing its own $6 billion lawsuit against Gazprom with the same Stockholm court to recover past "overpayment" for gas.
The pricing dispute between Russia and Ukraine -- the third in a decade -- could threaten European gas supplies.
With reporting by Reuters and Interfax