Meghan Markle's Suits co-star sends heartfelt congratulations message

The star of US television series Suits has officially handed his on-screen fiancée over to her real one, British royal Prince Harry.

Patrick J Adams, who plays Mike in the legal drama, first offered up a joke response to the news Meghan Markle was engaged before writing an endearing message to her and Harry.

"She said she was just going out to get some milk…" he wrote on Twitter initially, linking to the Kensington Palace announcement.

However, a few hours later, he posted a more meaningful post commemorating the newest royal couple.

"Playing Meghan's television partner for the better part of a decade uniquely qualifies me to say this," he began in a post on Instagram.

"Your Royal Highness, you are a lucky man and I know your long life together will be joyful, productive and hilarious.

"Meghan, so happy for you, friend. Much love."

Prince Harry and Markle will marry within the next six months, it has been announced.

Newshub.