U.S. President Barack Obama puts his hand on Chicago Mayor Rahm Emanuel's shoulder as they visit a campaign office in Chicago February 19, 2015. Emanuel, Obama's former chief of staff, has faced declining approval ratings among black voters as he seeks a second term in city elections next week. (REUTERS/Kevin Lamarque)

CHICAGO -- President Obama sought to give his former chief of staff a boost in his reelection campaign Thursday, stopping at one of Mayor Rahm Emanuel's campaign offices after praising him at the city's first ever national monument dedication.

Obama stopped by a South Side office where he mingled with volunteers making calls for the mayor's reelection effort, according to a White House pool report.

"It's great to see all of you here," Obama said at the office in the Kenwood neighborhood, according to the report. "I love phone banking."

Earlier in the afternoon, Obama dedicated three national monuments, including the Pullman National Monument here in Chicago. The Pullman Park district was the birthplace of the country’s first African American labor union.

Emnauel introduced Obama at the event. Obama, who has endorsed his first White House chief and cut a radio ad for him, praised the mayor.

"Before Rahm was a big-shot mayor, he was an essential part of my team at the White House during some very hard times for America," said Obama.

The trip came as Emanuel has been heavily courting African American voters in his final push ahead of Tuesday's election. Polls show he is at risk of being forced into a runoff against Cook County Commissioner Jesus "Chuy" Garcia, a liberal upstart.

"I'm glad he's my mayor, and I'm glad he's going to be my mayor for another four years," Obama said at his campaign stop.