The owners of the NFL have approved the introduction of a policy that requires all players to stand during the national anthem in a bid to prevent kneeling protests against inequality and police brutality in the US.

Those who do not show appropriate respect for the anthem will see their clubs fined. Players will, however, have the option to remain in the locker room during the national anthem.

"This season, all league and team personnel shall stand and show respect for the flag and the anthem," NFL commissioner Roger Goodell said in a statement. "Personnel who choose not to stand for the anthem may stay in the locker room until after the anthem has been performed.

"We believe today's decision will keep our focus on the game and the extraordinary athletes who play it - and on our fans who enjoy it."

A vote on the policy took place at the conclusion of the league's spring meetings and was approved by all 32 owners.

After months of discussions, owners believe the new policy will bring to an end kneeling protests while stopping short of requiring every player to stand.

Goodell added that the NFL is "dedicated to continuing our collaboration with players to advance the goals of justice and fairness in all corners of our society."

The league is currently being sued separately by Colin Kaepernick and Eric Reid, former San Francisco 49ers players who began the kneeling movement in 2016. The pair allege that NFL teams have colluded to keep them unemployed, with reports last week claiming depositions had proven that several teams had scouting reports grading Kaepernick as a starter-quality player.