Katy Perry doesn't think Meghan Markle's wedding dress fit her properly.

The 33-year-old singer - who is dating Orlando Bloom and was previously married to Russell Brand - insisted she was only being ''truthful'' when giving her critique of the Givenchy gown worn by the new Duchess of Sussex when she wed Prince Harry at the weekend.

She said: ''I would have done one more fitting.

''I'm never not going to tell the truth! One more fitting, but I love you.''

And the 'Roar' hitmaker admitted she much preferred the Alexander McQueen gown which the then-Kate Middleton - who is now known as Duchess Catherine - wore when she married Prince William in 2011.

She declared to 'Entertainment Tonight': ''Kate, Kate, Kate won, Kate won!''

However, despite her criticism of the wedding dress, Katy insists she has a lot of ''support'' for Meghan and wishes the former 'Suits' star well in her marriage to the British prince.

She said: ''I'm so happy for them, and, you know, I don't know them from Adam, but it's amazing what she's doing with all this, her humanitarian efforts.

''You know, the fact that she's a proud feminist, I love all that. I support her as another woman and love her and wish them both well.''

Meanwhile, Katy's fellow 'American Idol' judge Lionel Richie, 68, thinks Harry's late mother, Princess Diana, would have been ''very proud'' if she could see the 33-year-old prince and his brother William, 35, today.

He gushed: ''I remember when [Princess Diana] had them, Lady Di, and it was amazing. Now to see them both married and kids, well not yet, but married.

''She would be very proud. I must tell you, I mean, it's a moment in time, but I'm glad to see they're moving on as young men now, as family men. I love that.''