World leaders mark WWI centenary in Paris

It's been 100 years since the end of the first World War and world leaders have gathered in Paris to mark the event. The armistice treaty came into effect on the eleventh hour, of the eleventh day of the eleventh month in 1918 after four years of war. As part of a ceremony at the Arc de Triomphe renowned cellist Yo-yo Ma played performed at the foot of the Arc de Triomphe. President Trump also attended Sunday's event but on Saturday caused controversy by cancelling a trip to a cemetery for the war dead because of bad weather. He is not attending the Paris Peace Forum either which is being held after the armistice ceremony. He did speak a short time ago at Suresnes American Cemetery, just outside Paris, where 1,541 Americans who died in World War I are buried. Our correspondent in Paris is Peter Allen. He talks to Susie Ferguson.