Melania Trump's fashion has royal watchers comparing her to Princess Diana

The crisply tailored outfit reminded royal watchers of an iconic outfit Princess Diana wore. Photo / Getty Images

First Lady Melania Trump has arrived in the UK with her husband, US President Donald Trump for a three-day state visit.

Mrs Trump cut an elegant figure in a crisply tailored Dolce & Gabbana dress and a matching broadbrimmed Hervé Pierre hat and navy Manolo Blahnik shoes.

But there was something special about the white and navy ensemble that had royal observers drawing comparisons between Melania and Princess Diana.

Melania Trump wore a Dolce & Gabbana dress and a matching broadbrimmed Hervé Pierre hat for the first day of the state visit to Britain. Photo / Getty Images

It is not known whether Mrs Trump, 49, chose the outfit she wore to lunch at Buckingham Palace to pay tribute to a similar design worn by Princess Diana on the 50th anniversary of VJ Day in 1995.

Princess Diana wore several immaculate outfits in white and navy throughout the 1980s and '90s.

Diana, Princess of Wales, wore several immaculate outfits in white and navy throughout the 1980s and '90s, inclduing this outfit on the VJ Day 50th anniversary in 1995. Photo / Getty Images

Other royal watchers noted that Mrs Trump's fashion inspiration may have been inspired by two other "English roses:" Audrey Hepburn's character of Eliza Dolittle in My Fair Lady; and Kate Winslet's character of Rose from Titanic.

The Trumps enjoyed lunch with the Queen at Buckingham Palace after a welcome to mark the official start of their three-day state visit.

The President and Mrs Trump were greeted outside the palace by Her Majesty Queen Elizabeth II, Prince Charles and the Duchess of Cornwall.

President Donald Trump and first lady Melania Trump at Westminster Abbey in London. Photo / Getty Images

Camilla was perfectly co-ordinated with Mrs Trump in a chic white dress with A-line skirt and three-quarter-length sleeves complemented by two-tone tan shoes.

Both Melania Trump and Camilla, Duchess of Cornwall, wore white for the occasions. Photo / Ap

It is not known why the women chose to wear white — in celebration of summer or perhaps in acknowledgment of the suffragettes, perhaps, as was seen with Hillary Clinton and the woken in Congress who donned white for Mr Trump's State of theUnion address.

The Queen wore a turquoise suit dress with a floral print beneath.