Prince William and Duchess Catherine are "very excited" for Prince Harry and Meghan Markle.
The Duke and Duchess of Cambridge were delighted to hear the pair - who have been dating for 16 months - have got engaged, and admitted they have enjoyed "getting to know" the 'Suits' actress.
A tweet on the official Kensington Palace Twitter account read: "The Duke and Duchess of Cambridge said of the engagement: "We are very excited for Harry and Meghan. It has been wonderful getting to know Meghan and to see how happy she and Harry are together."
Harry's grandparents Queen Elizabeth and Prince Philip are also "delighted" for the happy couple.
A message on the Royal Family Twitter account read: "The Queen and The Duke of Edinburgh are delighted for the couple and wish them every happiness."
Harry, 33, popped the question to the 36-year-old star in London earlier this month and their engagement was announced by Harry's father, Prince Charles.
In a statement, Charles, 69, said: "His Royal Highness, the Prince of Wales, is delighted to announce the engagement of Prince Harry to Ms. Meghan Markle.
"The wedding will take place in Spring 2018. Further details about the wedding day will be announced in due course."
"His Royal Highness and Ms. Markle became engaged in London earlier this month.
"Prince Harry has informed The Queen and other close members of The Royal Family.
"Prince Harry has also sought and received the blessing of Ms. Markle's parents.
"The couple will live in Nottingham Cottage at Kensington Palace."
A tweet on the Clarence House Twitter account read: "The Prince of Wales is delighted to announce the engagement of Prince Harry to Ms. Meghan Markle."
Harry was best man when William and Catherine - who have son Prince George, four, and two-year-old daughter Princess Charlotte - tied the knot on April 29, 2011.