Known for its seemingly endless rows of impeccable white tombstones and home to the gravesite of assassinated president John F Kennedy, Arlington is seared into the American psyche as the country's most hallowed ground.

But according to recently released plans that were to be publicly discussed Wednesday, it needs more room.

An enlargement proposal would see the cemetery's burial capacity increase by 40,000 to 60,000 spaces, meaning it could remain active into the mid-2050s, the US Army Corps of Engineers said.

"This is a critical milestone in progress and the important steps our nation is taking to extend the life of Arlington National Cemetery well into the future," said Karen Durham-Aguilera, executive director of Army National Military Cemeteries.

Work is proposed to begin in 2021 and wouldn't be completed until 2025.

The expansion calls for the realignment of major roads that funnel thousands of commuters into Washington daily.

Arlington is America's oldest military cemetery, having started in 1864 during the Civil War. More than three million people visit each year.