"To all of the veterans gathered here, as well as all of those looking on.
From the heart of a grateful nation.
Thank you for your service," Pence said in his remarks, after laying a ceremonial wreath.
U.S. President Donald Trump, meanwhile, was in New York City attending the Veterans Day parade.
More than 100,000 Americans died in World War One, after the United States declared war on Germany on April 6, 1917, driving the nation into a global conflict.
Although the United States entered the war in the later stage, many Americans had disagreed with the decision to join allies Britain, France and Russia, some viewing it as an endless fight between old European rivals.
The conflict erupted in 1914 after a teenage Bosnian Serb assassinated Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne, and his wife in Sarajevo.
That lit the fuse for a war that would rewrite the world order, spell an end to empires, and claim the lives of more than nine million soldiers.
World War One, also known as the Great War, ended when world leaders at the 11th hour on the 11th day of the 11th month signed an armistice ending four years of bloody battles.
Americans honor their war heroes, both living and dead, each year on Nov.
11 with ceremonies to mark Veterans Day, a national holiday.