President Joe Biden, Vice President Kamala Harris and Secretary of Veterans Affairs Richard McDonough participate in the Presidential Armed Forces Full Honor Wreath-Laying Ceremony at the Tomb of the Unknown Soldier at Arlington National Cemetery in Arlington,

President Biden reflected on the "sacred obligation" to honor and protect those who serve during his final Veterans Day appearance as commander-in-chief on Monday at Arlington National Cemetery. The big picture: The observance event and ceremonial wreath-laying mark Vice President Kamala Harris' first public appearance since her post-election speech Wednesday — and one of just a handful of appearances of the sort left in Biden's tenure.