"Demi and I knew going into our romantic relationship that it may not be an easy one," Jonas, 20, tells PEOPLE. "I realize over the time we have shared together that I feel I care more about our friendship right now. It was my choice to break up but I love her as a friend. She's been there for me when I needed her. I will continue to be her friend and be there for her."
Lovato, 17, took to Twitter to shoot down what she labeled erroneous reports.
"There are so many crazy rumors flying around today," she writes. "I'd like to clear a few things up. First, Joe and I did split but it wasn't over the phone. Things didn't work out but we'll remain friends. Secondly, I am NOT dating anybody already. Nothing is more important to me than the relationship I have with my fans. Just thought you guys should know this."
The pair, who first met on the set of Camp Rock in 2007 and went public with their relationship in March, will still tour together, starting July 27 in Dallas.
Reporting by MICHELLE TAN and SHARON COTLIAR