It was a major political shift in the Scandinavian country that had a decades-long history of welcoming refugees, but is grappling with a crime wave linked with immigration.

Center-left Prime Minister Magdalena Andersson conceded defeat with 99.9% of the vote from the weekend elections counted Wednesday. She said she would step down Thursday.

Populist Sweden Democrats leader Jimmie Akesson declared victory for the four-party bloc. He said his party would be "a constructive and driving force" in the work of rebuilding safety in Sweden. He said it was "time to put Sweden first."

The bloc that includes the Sweden Democrats — the country's second-largest party — won a thin majority in parliament. Though a few votes were outstanding they were not enough to sway the final outcome.

Prime Minister Andersson said that "the preliminary result is clear enough to draw a conclusion" that her center-left forces had lost power.

Andersson became Sweden's first female prime minister last year and led the country in its historic bid to join NATO following Russia's invasion of Ukraine.