US Defense Secretary Lloyd Austin signed the agreement with Swedish Defense Minister Pal Jonson, the Pentagon said.

The defense pact paves the way for "US forces to operate in Sweden, including the legal status of US military personnel, access to deployment areas (and) prepositioning of military materiel," a Pentagon statement said.

The two "agreed on the importance of continued robust support to Ukraine in the face of Russia's illegal and full-scale invasion," it added.

Russia's February 2022 invasion of Ukraine spooked long-neutral Finland and Sweden, and both nations applied to join the North Atlantic Treaty Organization.

Finland acceded to the defense alliance in April, while Sweden awaits approval from treaty members Turkey and Hungary.

The new US-Sweden defense pact "will apply seamlessly before and after Sweden's accession" to NATO, a State Department statement said, adding that Sweden "is a strong, capable defense partner that champions NATO's values."