Russian President Vladimir Putin is warning that Russian authorities will take action against foreign oil companies that fail to meet environmental regulations and other licensing agreements.
Mr. Putin spoke Wednesday in Sochi, at a regional conference of energy ministers from Black Sea countries.
Last week, Moscow revoked environmental approval for the huge Sakhalin-2 project, run by Royal Dutch Shell on Russia's Pacific coast. However, Russia's Natural Resources Ministry later gave Royal Shell and other investors another month to fix any environmental problems at Sakhalin before any action is taken.
Earlier Wednesday, Russian Foreign Minister Sergei Lavrov said an ongoing Sakhalin environmental impact study is intended to make sure investors meet their obligations. He says the study does not indicate that the project's license will be revoked.
Japanese firms Mitsui and Mitsubishi have a combined 45 percent stake in the project, which is led by the British-Dutch oil giant, Shell.
Japan's ambassador to Russia criticized the threat to suspend the project as one-sided and lacking transparency. He warned that it could hurt Russia's image among international investors.
Some information for this report was provided by AFP and AP.