LONDON (Reuters) -Britain's King Charles and other senior royals joined veterans and crowds to watch a grand military parade and flypast at the start of four days of commemorations marking the 80th anniversary of Victory in Europe (VE) Day.

The government has planned a series of events in the run-up to the anniversary of Nazi Germany's unconditional surrender that took effect on May 8, 1945. It is observed around that date in many countries, including France, the United States and Russia.

The celebrations, which come as U.S. President Donald Trump is pressing for a deal to end the Russia-Ukraine war, kicked off on Monday when London's famous Big Ben clock struck at midday and extracts from British war leader Winston Churchill's VE Day speech were read out.

"My dear friends, this is your hour. This is not victory of a party or of any class," actor Timothy Spall said, reciting the words spoken by Churchill to cheering crowds eight decades ago.

"It's a victory of the Great British nation as a whole. We were the first, in this ancient island, to draw the sword against tyranny."

More than 1,300 members of Britain's armed forces marched through central London from outside parliament to Buckingham Palace, watched by the king, who offered a salute as they passed, alongside Queen Camilla, Prince William and his wife Kate, Prime Minister Keir Starmer, and veterans of the conflict.

Ukrainian armed forces also took part, carrying their nation's blue and yellow flag, in a gesture that underlined Britain's continued support for Ukraine in its war with Russia.

'SELFLESS DEDICATION'

Addressing the British veterans in an open letter, Starmer said: "I want you to know: the whole nation is inspired by the selfless dedication of your example."

"This week, the country will show you just how thankful we all are. Because we know, that without your service, the freedom, peace and joy that these celebrations embody, would not be possible," he said in the letter published by the government.

In 1945, VE Day was greeted by wild celebrations in London and across Britain.

The late Queen Elizabeth, then a 19-year-old princess, and her younger sister Margaret famously slipped out to join the throng outside Buckingham Palace, believed to be the only time during her 96 years she mingled with the public unrecognised.

Monday's parade concluded with a flypast by historic military aircraft and the Royal Air Force's Red Arrows display team, watched by the royals from the balcony of Buckingham Palace, as crowds, many of them carrying national flags - the red, white and blue Union Jack - flocked below to take in the spectacle.

The royals, who waved to the onlookers gathered outside, were also due to host about 50 veterans and others who lived through the war for a tea party inside the palace.

(Reporting by Michael Holden and Muvija M; Editing by Ros Russell and Gareth Jones)