(CNN) -- President Barack Obama will file the official paperwork within weeks to begin collecting money for his re-election campaign in 2012, which will cost more than his successful 2008 run, top aide David Axelrod told CNN this week.
In an exclusive interview with CNN Chief National Correspondent John King, Axelrod said field organizers would begin fanning out in targeted states by early spring to kick off the campaign effort.
"You know, I think we can have people there pretty early," Axelrod told King. "We believe very strongly in grassroots organizing. We believe that elections are determined not by ... political decisions made in Washington, but by decisions that people make at the grassroots, and that the most effective salespeople for a ticket or party or candidate are neighbors talking to neighbors."
Calling such campaigning a "labor intensive process," Axelrod said "we'll have people working very, very soon," adding: "I think the process will begin in the spring."
While he refused to offer a specific figure for the expected cost of the re-election effort, Axelrod did not object when King noted some Obama loyalists have suggested the cost this election cycle could exceed $1 billion.
In 2008, Obama raised more than $700 million in what was the most expensive presidential race in history.
Axelrod was Obama's senior adviser in the White House until he returned to Chicago, Illinois, at the start of February to begin organizing the re-election effort.
The interview with Axelrod was broadcast in two parts on "John King USA" on Tuesday and Wednesday.