• Kate Middleton joined the royal family at the annual Commonwealth Day service at Westminster Abbey Monday
  • She sported earrings and a necklace that she previously wore to meet Ukraine President Volodymyr Zelensky in 2020
  • The jewelry set is believed to be from Princess Diana's collection

Kate Middleton continues to show her support for Ukraine through her fashion.

The Duke and Duchess of Cambridge joined other members of the royal family at Westminster Abbey Monday for the Commonwealth Day service. Prince William and Middleton were joined by Queen Elizabeth II's cousin Princess Alexandra, Prince Charles and his wife Camilla, Duchess of Cornwall.

For the service, Middleton wore a Catherine Walker wool crepe coat dress with a silk velvet collar, the blue color of which reflected one of the colors of the Commonwealth's flag. She accessorized with a matching blue hat and carried a pair of gloves.

However, her sapphire and diamond earrings and necklace during the service appeared to send a message of support to the Ukrainian people amid Russia's invasion of their country, People noted.

The duchess wore the same earrings and necklace back in October 2020 to meet Ukraine's President Volodymyr Zelensky at Buckingham Palace, blogger The Court Jeweller pointed out on Twitter.

At the time, Middleton paired the jewelry with a cornflower blue belted dress when she and Prince William held an audience with Zelensky and his wife, Olena.

The jewelry set is believed to be from Princess Diana's collection. It was a perfect match for the late royal's sapphire engagement ring that Middleton now wears.

This wasn't the first time Middleton has shown her support to Ukraine using her clothing and jewelry, according to Page Six. Earlier this month, she wore a flag pin and an Alexander McQueen sweater in Ukrainian blue to visit a Ukrainian cultural center in London.

The Duke and Duchess of Cambridge first voiced their support for Ukraine last month via a statement posted to the official Kensington Palace Twitter account.

"In October 2020, we had the privilege to meet President Zelenskyy and the First Lady to learn of their hope and optimism for Ukraine's future," Prince William and Duchess Kate tweeted.

"Today we stand with the President and all of Ukraine's people as they bravely fight for that future," they continued, adding an emoji of the Ukraine flag.

The couple ended the message with their initials, "W & C."

The Ukrainian president responded to Prince William and Middleton's tweet, saying that he and his wife Olena "are grateful to the Duke and Duchess of Cambridge @RoyalFamily that at this crucial time, when Ukraine is courageously opposing Russia's invasion, they stand by our country and support our brave citizens."

"Good will triumph," he added.

Commonwealth Day is an annual event that celebrates the 54 member countries and 2.5 billion people around the world who come together to make the Commonwealth of Nations. This year's service marks the first time it was held in person since 2020.

Prince William and Kate Middleton
BURNLEY, ENGLAND - JANUARY 20: William, Duke of Cambridge and Catherine, Duchess of Cambridge during a visit to the Church on the Street on January 20th, 2022 in Burnley, England. Danny Lawson - WPA Pool/Getty Images