Duchesses of Cambridge and Cornwall congratulate Prince Harry and Meghan Markle

Prince Harry and Meghan Markle Credit: PA

The Duchess of Cornwall has expressed her delight at the news of Prince Harry's and Meghan Markle's engagement, saying "America's loss is our gain".

Prince Harry and Ms Markle announced their engagement through Clarence House on Monday, after 16-months of dating.

The couple will marry in May 2018 at St George's Chapel at Windsor Castle, the same venue that Prince Charles was blessed in a union with Camilla in 2005,

"Sometimes, in a climate when we're surrounded by a lot of bad news, it's a real joy to have a bit of good news for once. We're delighted," the duchess said.

The Duchess of Cambridge said she is "absolutely thrilled" at the news of as she congratulated the couple.

She smiled widely when asked about her reaction to the upcoming royal wedding as she made a trip to the Foundling Museum in London.

The wedding is set to take place in May 2018, although the exact day is yet to be confirmed.

A spokesman for Prince Harry said the wedding "will reflect who they are as a couple".

The royal family will pay for the wedding, including the church service, the music, the flowers and the reception, Kensington Palace said.

One of the only details that is known about the wedding is that there will be no bank holiday on the day, with Downing Street saying there were "no plans" for one.

Although no date for the wedding has been announced, it is thought that one will already have been agreed on, with royal diaries synced to ensure that everyone can attend.

It is expected that Justin Welby, the Archbishop of Canterbury, will marry the pair, after he disclosed that the couple had "chose to make their vows before God".

He continued that he was "absolutely delighted" by the news of the engagement and wished the pair "many years of love, happiness and fulfilment".

Prince Harry said his mother would have been 'over the moon' at the news of the engagement. Credit: PA

An interview with the couple was released on Monday afternoon in which the pair revealed details of how the fifth-in-line to the throne proposed, what they believed Princess Diana would make of the announcement, and what happened when Ms Markle met the Queen.

Earlier on Monday, the couple appeared in public together for a brief photo opportunity in the Sunken Garden at Kensington Palace, where they stood hand in hand and waved at well wishers.

During the photo opportunity, Prince Harry declared he was "thrilled" and "over the moon" following the announcement, and admitted he had known the American actress was "the one" from the moment they met.

"When did I know she was the one? Very first time we met," the prince said.

As the couple posed for photos, Ms Markle's engagement ring - which was designed by Prince Harry and contains three stones, two of which are diamonds from Princess Diana’s personal collection - could be seen.

he ring was designed by Prince Harry and has two diamonds from Princess Diana's collection. Credit: PA

In the couple's first television interview on Monday, the prince said his late mother Princess Diana would have been "over the moon" at the news of his upcoming marriage.

"She would be jumping up and down, so excited for me, but then would probably have been best friends with Meghan," he added.

In the interview Ms Markle also revealed that Prince Harry proposed while the pair were roasting a chicken.

The 36-year-old recounted how "it was just an amazing surprise, it was so sweet and natural and very romantic, he got on one knee".

Asked if it was an instant 'yes' from her, the Suits actress said: "Yes, as a matter of fact I could barely let [Harry] finish proposing, I said can I say yes now?"

To which Prince Harry replied: "She didn't even let me finish, then there was hugs and I had the ring on my finger and I was like can I do the ring and she said 'oh yes do it', so no it was a really nice moment, just the two of us and I think I managed to catch her by surprise as well".

  • Prince Harry and Meghan Markle's engagement interview in full

The couple are thought to have met the Queen for afternoon tea prior to their engagement, as they needed her approval before going ahead with it.

Ms Markle described Elizabeth II as an "incredible woman", and it was also disclosed that she had become a firm favourite with the corgis.

Prince Harry said he felt responsible for what he was asking Ms Markle to do with regards to joining the Royal Family. Credit: Pool

Prince Harry also said he said he feels a sense of responsibility for what he is asking Meghan to do with regards to joining the Royal Family.

"That sense of responsibility was essentially from day one or maybe a couple of months in when I suddenly realised actually this is, you know I feel, I know that I'm in love with this girl and I hope that she's in love with me but we still had to sit down on the sofa and still had to have some pretty frank conversations with her and say 'what you're letting yourself in for is, it's a big deal".