Commissioner Adam Silver announced on Tuesday that Sterling was banned and fined $2.5m (£1.5m) for making racist remarks to his girlfriend, but James believes that further action must be taken to ensure that the Los Angeles Clippers owner does not remain in the NBA.
"It's a monumental day and it's going to be remembered in NBA history," James told reporters after Miami Heat's practice session on Wednesday. "But the job is still not done. It's a win, but we still need the owners to do their part.
"We're fighting to get an owner out of our league who shouldn't be a part of our league. No matter how long it takes, no matter how much money it costs, we need to get him out of there, and whoever is associated with him doesn't belong in our league."
Oprah Winfrey is one of a number of people to have expressed an interest in buying the Clippers.