Naomi Watts says Prince Harry's wedding is 'so romantic'

Naomi Watts thinks Prince Harry's romance with Meghan Markle is "lovely".

The 49-year-old actress - who played Harry's mother Princess Diana in a 2013 biopic - has admitted she's looking forward to seeing the 33-year-old royal tie the knot with the American beauty at St George's Chapel at Windsor Castle on May 19.

The actress - whose movie about the late Princess, 'Diana', stirred controversy - told People: "I think it's lovely. It's the union of two people, making a promise, there's nothing better than that, it's so romantic."

'Diana' focused on the last two years of the Princess' life, when she was rumoured to have been in a relationship with cardiologist Hasnat Khan and later, Dodi Fayed.

At the time, the movie was widely panned by critics and Naomi subsequently admitted she had mixed feelings about playing the British icon.

Naomi - who has sons Alexander, 10, and Samuel, nine, with her ex-husband, actor Liev Schreiber - previously said: "I was a little bit torn."

More specifically, the actress was concerned by how the Princes, William and Harry, would react to the film about their mother, who died in a car accident in Paris in 1997.

She confessed: "I do care deeply about how the princes feel, of course. I am a mum of two boys."

And Naomi admitted she felt especially uncomfortable about the situation when she came face-to-face with Prince William in a restaurant.

The Oscar-nominated star recalled: "There was actually quite an eerie moment in London when I did see Prince William in a restaurant, and I got very nervous, because if I caught his eye, I didn't want to interpret a look and think he had a negative feeling about this idea, so I made sure not to look."