In an exclusive interview in the April issue of ESSENCE, Warwick described Houston's death as "a huge, unexpected shock."
"It's a horrible blow to our entire family," she said. "I am inconsolable right now."
Warwick also had a message for the superstar singer's mourning fans. "What I'd like to say to Whitney's fans, whom she loved as much as they love her, is that they should hold those memories of Whitney close to their hearts and let that comfort them at this time," she said.
"If a favorite song of hers makes you feel a certain way, cherish that feeling and remember Whitney as the beautiful songbird she was."
For more of Dionne Warwick's exclusive interview with ESSENCE, pick up the April issue on newsstands now or subscribe here.