Gas supplier Gazprom will double its export capacity via the Baltic Sea when operations begin, which the project's operator said it expects by year-end.
Here are some significant moments in Nord Stream 2's development:
November: Gazprom and Western partners look into expanding the Nord Stream pipeline system by a further 55 billion cubic metres at an initial estimated cost of 9.5 billion euros ($11.3 billion).
June: Gazprom, Royal Dutch Shell, E.ON, OMV, Wintershall and ENGIE agree to build the pipeline.
March: Eight EU governments object on geopolitical grounds.
2017April: Financing agreements are signed.
January: Germany grants permits for construction and operation.
January: The U.S. ambassador to Germany says companies involved in NS 2 could face sanctions.
December: Swiss-Dutch company Allseas suspends pipe-laying.
U.S. President Donald Trump signs a defence policy bill including sanctions.
May: Germany's energy regulator declines to grant a waiver of EU gas directives to the operators, while an EU court also throws out a challenge to the rules.
Sept. 3: Pressure mounts on Berlin to reconsider support after the alleged nerve agent attack on Kremlin critic Alexei Navalny.
Sept. 23: The world's largest group of shipping insurers says it will not insure vessels involved in NS 2.
Oct. 1: Denmark gives NS 2 permission to operate in Danish waters.
Dec. 3: The United States unveils a bill targeting companies and individuals helping NS 2.
Dec. 28: NS 2 says it has completed the 2.6 km section in German waters.
Jan 20: Trump on his last full day in office imposes sanctions on Russian pipe-laying ship Fortuna.
German environmental groups file complaints with maritime regulator BSH, effectively preventing further work in Germany for the time being.
Jan. 21: The European parliament passes a resolution calling for a stop to NS 2 completion in response to the arrest of Navalny in Russia.
Jan. 24: Fortuna resumes work in Danish waters.
April 22: The U.S. Senate Foreign Relations Committee advances a bill to pressure companies helping to build NS 2.
May 19: The U.S. State Department waives sanctions around participants of Nord Stream 2, saying it was in the U.S. national interest.
June 4: President Vladimir Putin says Russia has finished laying the first line of the pipeline to Germany.
June 7: U.S. Secretary of State Antony Blinken says completion of Nord Stream 2 is a "fait accompli", defending the U.S. decision to waive some sanctions and vowing a response if Moscow tries to use gas as a weapon.
June 10: Nord Stream 2 says the project will start preparations to fill the first of two pipelines with natural gas within a few months.
July 22: The United States and Germany announce an agreement on NS 2 under which Berlin also pledged to respond to any attempt by Russia to use energy as a weapon against Ukraine and other Central and Eastern European countries.
July 28: The pipeline operator says NS 2 is 99% complete.
Aug 20: The Biden administration slaps sanctions on a Russian ship and two companies involved in the pipeline.
Putin says there are 15 km (9 miles) left to finish NS 2.
Aug 25: Duesseldorf Higher Regional Court rules that Nord Stream 2 is not exempt from European Union rules that require the owners of pipelines to be different from the suppliers of the gas that flows in them to ensure fair competition.
Sept 6: Russian pipelaying vessel the Fortuna welded the final piece of pipe into place, the project's operating company said.
(Reporting by Tommy Lund and Bartosz Dabrowski in Gdansk; editing by Jason Neely)