The US Senate voted overwhelmingly to approve the accession of Sweden and Finland to NATO, with the resolution gaining the support of 95 senators.
The single dissenting vote came from Republican Senator Josh Hawley of Missouri, who argued that there should be less focus on security in Europe and much more on the threat from China, dpa news agency reported.
US President Joe Biden has strongly backed the accession of Finland and Sweden to NATO, and referred the matter to the Senate for consideration in July.
The vote in Washington followed a vote in France's National Assembly earlier on Wednesday, in which 209 deputies voted in favour of Swedish and Finnish membership, while 46 voted against. The Senate, the second chamber of the French parliament, voted to approve the accession a fortnight ago.
Sweden and Finland applied to join the Western defence alliance in the wake of the Russian invasion of Ukraine. Until now, the two countries have been close partners, but not members, of NATO.
Before the accession protocols can enter into force, they must be ratified by all 30 NATO member states, two-thirds of which have already given their approval for the new members.