Tagliabue made the comment during his annual state of the league address at the site of Sunday's Super Bowl at Jacksonville, Fla.
Los Angeles, the nation's second-largest television market, has been without a team since the Raiders and Rams left following the 1994 season.
"What matters is two teams left LA and we want to get back there," Tagliabue said. "What matters is we get this right. We want to get it done within this decade and when we do it we want it to stay there."