The remaining four countries that are still to issue permits are Russia, Finland, Sweden, and Denmark. Part of the pipeline's undersea sections will lead through those countries' territories. The coordinator and future operator of the pipeline, Switzerland-based Nord Stream 2 AG, said it expects the permits to be issued within the next few months.

Construction will begin still this year, just as planned, Nord Stream 2 AG said.

Germany's Federal Maritime and Hydrographic Agency said on Tuesday that it approved the 31-kilometer section of the pipeline to be built on German territory.