Kate Middleton appeared to show her support for Ukraine in a blue coatdress paired with Princess Diana's jewelry

The Duchess of Cambridge previously wore Princess Diana's necklace and earrings to meet Ukraine's President Volodymyr Zelenskyy.

• Kate Middleton stepped out in a Catherine Walker coatdress on Commonwealth Day. 
• The duchess' necklace and earrings, believed to have been Princess Diana's, had a special meaning.
• She previously wore them to meet Ukraine's President Volodymyr Zelenskyy, People reports.

The Duchess of Cambridge wore a coatdress and matching jewelry with a hidden meaning for a Commonwealth Day service on Monday. 

Kate Middleton appeared to send a message of support for Ukraine with her ensemble, which was entirely blue, one of Ukraine's national colors.

—The Duke and Duchess of Cambridge (@KensingtonRoyal) March 14, 2022

Arriving at the event at London's Westminster Abbey, Middleton was photographed wearing a Catherine Walker coatdress and Lock & Co hat, the Daily Mail reports.

She completed the look with sapphire earrings and a necklace, believed to be from Princess Diana's collection, People reports. The publication added that the duchess was previously photographed wearing the jewelry to meet Ukraine's President Volodymyr Zelenskyy and his wife, Olena Zelenskyy, at Buckingham Palace in October 2020. 

The Duke and Duchess of Cambridge stepped in for the Queen and hosted an audience with the couple during their two-day visit to the UK. 

Middleton and Prince William have been vocal in their support for Ukraine amid Russia's invasion of the country.

"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," the couple wrote in a joint statement to their Twitter account on February 26.

"Today we stand with the President and all of Ukraine's people as they bravely fight for that future," they added.

The duke and duchess visited the Ukrainian Cultural Centre in London last week, where they delivered trays of chocolate brownies and granola bars to the volunteers, The Independent reported.

They also offered the services of their charitable foundation for any young people affected by the war who may need assistance with their mental health, the publication added.

Kensington Palace did not immediately respond to Insider's request for comment.