The Duke and Duchess of Sussex, who are living in California after quitting royal duties, published a statement on their Archewell website on Thursday.
The couple said: “Prince Harry and Meghan, The Duke and Duchess of Sussex and all of us at Archewell stand with the people of Ukraine against this breach of international and humanitarian law and encourage the global community and its leaders to do the same.”
Harry and Meghan’s statement comes after Russia launched an invasion on Ukraine on Thursday in the biggest attack on a European state since World War Two.
Vladimir Putin hit the country with early morning attacks, targeting cities and bases with air strikes in an ambush which the West feared had been coming for weeks.
Ukrainian President Volodymyr Zelensk declared martial law and has called on citizens to volunteer to fight for their country.
Mr Zelensk said: “We will give weapons to anyone who wants to defend the country. Be ready to support Ukraine in the squares of our cities.”
Boris Johnson told ministers it is “a dark day in the history of our continent” following the invasion of Ukraine.
The Prime Minister held a Cabinet meeting on Thursday evening, which followed a Cobra meeting.
Mr Johnson told ministers Mr Putin has launched “a cynical and brutal invasion for his own vainglorious ends”, a No 10 spokesman said.
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The spokesman said: “He said the UK could be proud of the actions it has…