Germany on Friday ratified Finland's and Sweden's accession to NATO, three days after the 30 members signed off on the most significant expansion of the alliance on Tuesday.
The parliament in Berlin as well as the Bundesrat grouping the federal states endorsed the accession protocols for both Nordic countries.
"This creates more security - for all NATO members and for Europe," German Chancellor Olaf Scholz said on Twitter.
The documents need to be ratified by the parliaments of all 30 North Atlantic Treaty Organization members before Finland and Sweden can be protected by the NATO defence clause that states that an attack on one member is an attack against all.
Ratification is likely to take up to a year but in the meantime Helsinki and Stockholm can already participate in NATO meetings and have greater access to intelligence.
Moscow has repeatedly warned both countries against joining NATO. On March 12, the Russian foreign ministry said "there will be serious military and political consequences".
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