The US president said the music industry has lost a ''legend far too soon'' after the 63-year-old singer passed away yesterday morning (17.05.12) following her battle with cancer.
He explained: ''Her voice was unforgettable. The music industry has lost a legend far too soon.''
Music producer Pete Waterman, Dolly Parton, Kylie Minogue and Sir Elton John have also paid tribute to the 'Love to Love You Baby' hitmaker, and Barbra Streisand - who teamed up with Donna on 1979 hit 'No More Tears (Enough Is Enough)' - was ''shocked'' to hear about the music legend's passing.
Dolly wrote on her website: ''I can't believe we've lost another wonderful singer. She was the disco queen, and will remain so. I knew her and found her to be one of the most likable and fun people ever.''
Pete told BBC News: ''She was the icing on the cake. We were at the top of our game when we worked with her. She was just fantastic.
''Donna was unique. Donna did things Donna's way. One of the first things she said to me was, when you work with me, you work on Donna time... She wasn't a diva, she was inspirational. Her talent came from God, she knew she couldn't just turn it on.''