Suits co-star's message to Meghan Markle

Prince Harry and Meghan Markle's engagement has prompted an outpouring of congratulations online, including an adorable response from her former Suits co-star.

Markle starred as Rachel in seven seasons of the TV drama alongside her on-screen husband, Mike, played by actor Patrick J Adams, before leaving the series to pursue her new life in London.

Meghan Markle as Rachel Zane, Patrick J. Adams as Michael Ross. Photo / Getty

"Playing Meghan's television partner for the better part of a decade uniquely qualifies me to say this: Your Royal Highness, you are a lucky man and I know your long life together will be joyful, productive and hilarious," Adams tweeted today, in response to the engagement news.

Playing Meghan’s television partner for the better part of a decade uniquely qualifies me to say this: 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.

— Patrick J Adams (@halfadams) November 27, 2017

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

Earlier, Adams posted a tongue-in-cheek tweet with a photo of the newly engaged royals: "She said she was just going out to get some milk …"

Suits star Gabriel Macht — who plays main character Harvey Specter — and the show's creator Aaron Korsh also offered their congratulations.

Congrats to @meghanmarkle and Prince Harry. Sending all my best for your upcoming nuptials and a long happy life together. #love

— Gabriel Macht (@GabrielMacht) November 27, 2017

Congratulations to Meghan Markle and Prince Harry on their engagement. Wonderful news, I wish you both a lifetime of happiness. Love, Aaron

— Aaron Korsh (@akorsh9) November 27, 2017

Other notable public figures including Hollywood stars and politicians took to Twitter in the wake of the engagement.

Michelle and I are delighted to congratulate Prince Harry and Meghan Markle on their engagement. We wish you a lifetime of joy and happiness together.

— Barack Obama (@BarackObama) November 27, 2017

Can’t Prince Harry and his American girlfriend run our country? They seem nice.

— Chelsea Handler (@chelseahandler) November 27, 2017

Congratulations Prince Harry and Meghan Markle! 😊🤗🍾❤️🙏🏽

— Khloé (@khloekardashian) November 27, 2017

In their first interview as a couple, Harry said he decided to pop the question on a "cozy night" at Nottingham Cottage at Kensington Palace after dating Markle for about 18 months.

Prince Harry and Meghan Markle during an official photocall to announce the engagement of Prince Harry and actress Meghan Markle at The Sunken Gardens. Photo / Getty

"It happened a few weeks ago, earlier this month, here at our cottage; just a standard typical night for us … trying to roast a chicken," Harry said, in an interview with the BBC.

Ms Markle said the proposal was "an amazing surprise".

"It was so sweet and natural and very romantic. He got on one knee," she said.

Asked whether it was an "instant yes", Prince Harry said "of course".