NEW YORK (AP) — Bill de Blasio began his second term as New York City mayor Monday at a swearing in ceremony outdoors in freezing temperatures, taking the oath of office administered by Brooklyn native and U.S. Sen. Bernie Sanders of Vermont.

"By Vermont standards this is a warm and pleasant afternoon," Sanders, joked the crowd at City Hall Park.

De Blasio won re-election handily in November, becoming the first Democrat to return to City Hall in New York since Edward Koch 1985.

He boasted about the city recording the lowest number of annual homicides since the early 1950s. The police department's preliminary count is 290 homicides for 2017, a 14 percent drop from the year before.

"We have brought police and community together like never before," De Blasio said. "We have dedicated ourselves to a vision of true neighborhood policing and it works."

As a national leader in progressive politics, de Blasio said he envisions a city that serves more than the elite and Wall Street titans.

"The deepest, truest stakeholders of this town are the people who do the work, who every day make this city come to life but have too often not reaped the rewards," he said. "We have a responsibility, every one of us, to ensure that New York remains a beacon to our nation and to our world."

Sanders, an independent who made an unsuccessful bid for the Democratic presidential nomination in 2016, praised de Blasio's work on providing pre-kindergarten education and other progressive issues.

"In this city, the largest city in our country, the people of New York under Bill de Blasio have chosen to move government in a very different direction than what we're seeing in Washington," Sanders said. "Instead of pandering to billionaires, we have a government here which has chosen to listen to the needs of working families."

Also sworn-in for second terms were fellow Democrats, Public Advocate Letitia James and Comptroller Scott Stringer.

The ceremony came on a frigid New Year's Day; it was about 14 degrees by early afternoon.