Prince Harry-Meghan Markel's wedding so romantic, says Naomi Watts

British actor Naomi Watts, who played Princess Diana in a 2013 biographical drama, finds Prince Harry's romance with Meghan Markle "lovely".

The 49-year-old star says she is looking forward to seeing the 33-year-old Royal tie the knot with the "Suits" star at St George's Chapel at Windsor Castle on May 19.

"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," Watts told People magazine.

"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.