U.S. President Barack Obama plans to honor the country's war dead by spending the Memorial Day holiday Monday with veterans and their families, as communities across the nation host their own festivities.

The president will visit the Vietnam Veterans Memorial, as well as Arlington National Cemetery just outside Washington, where soldiers have placed American flags on nearly 260,000 graves.

The first large-scale observance of what was originally called Decoration Day took place at the cemetery in 1868, three years after the bloody Civil War that killed more than 600,000 people.

Mr. Obama said in his weekly address that the holiday is a time for the country to honor those who made the ultimate sacrifice and to reaffirm its commitment to care for those who came home.

Many Americans have the day off from work and school, and the long weekend is seen as the unofficial start of the summer vacation season. Celebrations involving picnics or trips to the beach, parks or campgrounds are common.

The weather has affected many holiday plans this year, with thunderstorms cutting short an annual concert on the National Mall Sunday night and a tropical storm making landfall in the southeastern state of Florida.