- The ceremony will take place on the steps of City Hall on New Year's Day
- Former President Bill Clinton performed the swearing in for de Blasio in 2014
"Sen. Sanders is a proud son of Brooklyn and a dedicated advocate for working people ... (His) progressive leadership has helped reshape the American political debate in favor of men and women long left out of our city and nation's prosperity," de Blasio said in a statement to CNN on Wednesday.
In an interview with WNYC on Friday, de Blasio said he had asked Sanders to swear him in.
"He's a proud son of Brooklyn and someone we should all be proud of for what he has achieved," de Blasio said. "I asked him if he would be willing to swear me in and I'm honored that he has chosen to do it."
He continued: "I have immense respect for what he's done: He's single-handedly changed discussion in this country. No one has shined the light on the question of income inequality more than Bernie Sanders, and he's changed the way that politics will be approached in this country going forward."
Sanders will swear in de Blasio on the steps of City Hall.
The independent senator from Vermont is not the first political figure to conduct a swearing in for de Blasio. On a chilly first day of 2014, former President Bill Clinton administered the oath of office during de Blasio's first inauguration, using a Bible once owned by President Franklin Delano Roosevelt.
Frigid temperatures are expected to keep the 2018 inauguration from being as big as the first.
"It's term two, so naturally this will be a smaller-scale event compared to 2014," Jaclyn Rothenberg, spokeswoman for the mayor, told CNN. "It's going to be cold and weather could be an issue."
Public Advocate Letitia James, who became the first black woman to hold citywide office in New York in 2014, and Comptroller Scott Stringer will also be sworn at the ceremony.