John said that he is concerned about the path the 20-year-old controversial singer is headed on, reported Us magazine.
"I look at Miley Cyrus and I see a meltdown waiting to happen. And she's so young! But she's got two records in the top 20, so who is going to stop her?," John said.
The 66-year-old also added that Lady Gaga is "in a dangerous place."
"With Gaga - who I love, she's the godmother to our children - I'd like to be able to talk to her right now, but I can't get through to he. And there are times when you have to listen. When your persona begins to take over your music and becomes more important, you enter a dangerous place. Once you have people around you who don't question you, you're in a dangerous place," he said.