The R.I.P singer told Power 105.1 radio's show The Breakfast Club that she has moved on from her brief time with the Keeping up with the Kardashians star.
"I don't want to talk about this too much because people move onwards and upwards, and it was a phase," said Rita. "And it was a moment in my life and now it's like onwards and upwards."
Rita and Rob were spotted together on several occasions in 2012 and maintained a low profile until Rob claimed on Twitter that Rita had been unfaithful.
Rob Kardashian has entered rehab for depression
"It was a bit where I was like 'Really, dude?'" said Rita when quizzed about Rob's defamatory tweets. "But what I think is that people react to things differently and like to express their feelings in certain ways.
"I don't tend to use social media, so when that whole situation happened, silence for me is the biggest form of flattery and I love to just keep it moving unless I need to say something."
During the interview Rita also slammed rumours that she had an affair with Jay Z, who signed her to his Roc Nation label in December 2009, within 48 hours of her arrival in the US.
Rita Ora says Calvin Harris is her first love
Clearly outraged by such a suggestion, Rita told the radio hosts, "Don't you dare disrespect Beyoncé like that ever again in your entire life.
"You should know better than that, that's just straight up disrespect," she added. "You can't even go there."
Rita is currently dating Scottish DJ Calvin Harris.
Rita Ora and Calvin Harris
Discussing falling in love with 30-year-old Calvin, Rita revealed, "There are so many things. The fact that he got something out of me that I never thought I had. Yes, like falling in love. I just didn’t think I had it. I’d never experienced it before. And I was just like in the wilderness, thinking, “Will it ever happen?'"