OTTAWA - Prime Minister Stephen Harper is offering congratulations to Prince William and Kate Middleton on their engagement and wants them to visit Canada after the wedding.

Harper says Canadians offer warm wishes for the impending nuptials.

The prince announced the news Tuesday after an eight-year, on-and-off romance with Middleton.

The 28-year-olds met at University of St. Andrews in Scotland.

The engagement was sealed when the prince presented Middleton with a sapphire-and-diamond ring that had belonged to his mother, Princess Diana.

The couple are expected to wed next spring or summer and Harper hopes they'll come to Canada some time after that.

"It would be an honour to welcome Prince William and his bride to Canada in the future and show them the special warmth and cherished traditions that are reserved for members of the royal family," Harper said in a statement.

Prince William last visited Canada in 1998, on a private trip to Whistler, B.C., with his father and brother.

Liberal Leader Michael Ignatieff and NDP chief Jack Layton also welcomed the news.

"They're such a nice young couple, they look great, they look happy," Ignatieff said. "Reminds me of when I got engaged. It's nice."