The America's Got Talent host posted nearly 20 Tweets on Wednesday night addressing "this challenging time" for his family.
"What infuriates me most is to hear people slander @MariahCarey. I will forever be in debted to her for blessing me with our children," he wrote. "I will always love her unconditionally for this and so much more. @Mariah Carey is an amazing Mother and I trust her wholeheartedly..."
Cannon, 33, and Carey have been living apart for months, a source told PEOPLE in August.
Both the pop diva and TV personality have been photographed without their wedding rings.
The couple secretly tied the knot in 2008 after just weeks of dating, welcoming twins Monroe and Moroccan in 2011.
I love @MariahCarey and that will never change!!!— Nick Cannon (@NickCannon) September 3, 2014