Russia says it has completed the Nord Stream 2 gas pipeline to Germany.
And that could set the stage for fresh tensions with the U.S.
Washington strongly opposes the pipeline, saying it could leave Europe overly dependent on energy supplies controlled by Moscow.
Russian giant Gazprom began construction of the 745-mile connection five years ago.
The $11 billion project was briefly halted in 2019 after then U.S. President Donald Trump imposed sanctions on it.
Now the new pipeline will double Russia's gas exporting capacity to Europe via the Baltic Sea.
It also reduces its dependence on an existing route that runs through political foe Ukraine.
Earlier in the week, Russian foreign ministry spokesperson Maria Zakharova said Moscow was eager to start pumping:
It's down to Germany's regulator to give the green light, she says.
But that can't happen overnight.
Certification and completion of all paperwork is expected to take up to four months.
Ukraine stands to lose billions in transit fees if Moscow switches all supplies to Nord Stream 2.
Russian President Vladimir Putin says Kiev needs to show 'good will' if it wants to avoid that fate.