President Joe Biden and first lady Dr. Jill Biden on Tuesday attended a memorial mass for Beau Biden marking eight years since his death from cancer, according to the White House.

The Bidens attended the morning service at St. Joseph on the Brandywine Church in Wilmington, Delaware, before visiting the site of Beau Biden's grave, which is located behind the church.

During his Memorial Day address from Arlington National Cemetery, the president mentioned Beau Biden's death as he discussed the measures his administration has taken to help veterans. Beau Biden, who served as Delaware's attorney general before his death, served a tour in Iraq as a member of the Delaware National Guard.

"Tomorrow marks eight years since we lost our son Beau," he said. "Our loss is not the same -- he didn't perish in the battlefield, it was cancer that stole him ... after being deployed as a major in the United States Army National Guard in Iraq. As it is for so many of you, the pain of his loss is with us every day, but particularly sharp on Memorial Day."

Biden has said he believes there may have been a connection between the brain cancer that killed Beau Biden and the burn pits Beau Biden was exposed to during his tour in Iraq. Burn pits were commonly used to burn waste -- including trash, munitions, hazardous material and chemical compounds -- at military sites throughout Iraq and Afghanistan until about 2010.

These massive open-air burn pits, which were often operated at or near military bases, released dangerous toxins into the air that, upon exposure, may have caused short- and long-term health conditions, according to the Department of Veterans Affairs.