Russia is shutting down the Nord Stream One pipeline for annual maintenance beginning Monday morning.

The pipeline from Russia, which under the Baltic Sea, is Germany’s main source of gas, and is scheduled to be offline until July 21.

German officials have expressed doubts about Russia’s intentions, especially given the fact that Nord Stream operator Gazprom reduced the gas flow by 60% last month.

Gazprom has said the maintenance includes “testing of mechanical elements and automation systems.”

Gazprom also reported technical problems with parts of a turbine that its partner Siemens Energy sent to Canada for repair, but which could not be returned because of western sanctions on Russia over its invasion of Ukraine.

Canada, however, said over the weekend that it would allow the parts to be returned to Germany, citing the “very significant hardship” the insufficient gas supply will cause to German economy.

German Vice Chancellor Robert Habeck has said he suspected that Russia may cite “some little technical detail” as a reason not to resume gas deliveries to Germany after the maintenance is completed.

Some information in this report came from The Associated Press and Reuters.