President Barack Obama has declined to attend a dedication ceremony in October for a new memorial honoring American veterans who have been disabled fighting for their country in wars, according to sources close to the event.

The American Veterans Disabled for Life Memorial (AVDLM), the first such memorial of its kind, is set to be dedicated during a ceremony on Oct. 5 near the National Mall in downtown Washington, D.C.

However, Obama, who was first invited to attend the event in January, will not be among those in attendance, according to a source who is familiar with the situation. This would be among the first national memorials in recent history not to be formally accepted in person by a sitting U.S. president.

Organizers of the event were caught off guard when informed by the White House of the president’s decision this week and are hoping to receive an explanation from the White House as to why Obama will not be attending the ceremony, according to the source, who is involved with the memorial and was informed of the decision this week.

U.S. presidents have historically been on hand during dedication ceremonies for major memorials in D.C., including the Air Force memorial, the World War II memorial, the Vietnam War memorial, the Korean War memorial, and the Martin Luther King Jr. Memorial, which Obama attended and spoke at.

The White House declined to comment when asked by the Washington Free Beacon to confirm if Obama would be unavailable to attend the ceremony.

"It’s disappointing that the president is unable to celebrate the dedication of this historic memorial with the heroes that it honors—our nation’s disabled veterans," said the source.

Secretary of the Interior Sally Jewell is currently scheduled to attend the ceremony, as is Secretary of Veterans Affairs Robert McDonald.

The AVDLM memorial, construction of which recently finished, will honor the millions of disabled U.S. veterans who have fought in wars over the decades, including those with physical and mental injuries.

"The memorial will serve as a constant reminder of the cost of human conflict," the memorial’s organizers wrote in a recent press release sent to reporters.

The idea for the memorial originated in 1998 and led to the formation of the Disabled Veterans’ Life Memorial Foundation, which first approached Congress to initiate the lengthy authorization process before beginning to raise funds for the memorial.

It now stands completed on a 2.4-acre sight near the National Mall, just south of the U.S. Botanic Garden.