The Russia-led South Stream undersea gas pipeline is still going ahead, Energy Minister Alexander Novak was quoted as saying on Saturday, following concerns the European Union might be losing enthusiasm for the project.

The natural gas pipeline, which will cost an estimated $40 billion, is designed to carry Russian gas to the center of Europe on a route that bypasses crisis-hit Ukraine.

The project has yet to be approved by the EU, which is trying to become less dependent on Russian gas. Supplies from Russia currently account for about a third of EU gas imports.

"The South Stream project has not been stopped," Novak was quoted as saying by the Interfax news agency.

"The agreements which were signed remain in force. They can't be canceled on a unilateral basis."

The European Commission has said South Stream as it stands does not comply with EU competition law because it offers no access to third parties.

South Stream also runs counter to the EU policy of diversifying supply sources to reduce dependence on Russia.

The project has run into problems as a European Commission working group, set up to define a mechanism for managing the pipeline, has stopped its work, Novak said.

"We hope that we will resume such work when the new European Commission is appointed," the minister added.