There have been several reports in recent weeks quoting Aguilera saying Spears "let herself go" and she "can't see a comeback in the cards" for Spears, MTV.com reported Friday.
"It's really sad to see that some tabloid magazines still have to manufacture ill will between Britney and me," Aguilera said in a post on her Web site. "We are both grown-ups and have the utmost respect for each other personally and professionally.
"If certain journalists want to throw their integrity out the window by spreading false information, then so be it," she wrote. "But I'm not falling for their lies and neither should my fans or Britney's."