NFL commissioner Roger Goodell believes the league has been at fault for not listening to its players denouncing racism.

The United States is currently gripped by widespread protests over police brutality following the death of George Floyd in Minnesota last week.

And Goodell, who offered his condolences to the family of Floyd, said the NFL was wrong.

"It has been a difficult time for our country, in particular black people in our country," he said on a video posted on Twitter.

"We, the National Football League, condemn racism and the systematic oppression of black people.

"We, the National Football League, admit we were wrong for not listening to NFL players earlier and encourage all to speak out and peacefully protest.

"We, the National Football League, believe black lives matter.

"Without black players there would be no National Football League and the protests around the country are emblematic of the centuries of silence, inequality and oppression of black players, coaches, fans and staff.

"We are listening, I am listening, and I will be reaching out to players who have raised their voices and others on how we can improve and go forward for a better and more united NFL family."

Goodell's message came after a number of the NFL's leading players called on the league to denounce racism in a video.

The NFL has been locked in an ongoing debate during recent seasons with players over kneeling protests during the customary pre-game playing of the national anthem.

The practice was popularised by quarterback Colin Kaepernick, who is mixed race, in 2016 to protest racial injustice and police brutality.

Kaepernick, who in 2013 led the San Francisco 49ers to the Super Bowl but lost to the Baltimore Ravens, filed a grievance against the league in 2017, claiming collusion as no teams signed him after he parted ways with the Niners. The NFL and Kaepernick settled in 2019.

"Protests around the country are emblematic of the centuries of silence, inequality and oppression of black players, coaches, fans and staff," added Goodell. "I will be reaching out to players who have raised their voices and others on how we can improve."

The NFL sent the video out just hours after US President Donald Trump renewed his call for an end to kneeling protests during the national anthem.

"We should be standing up straight and tall, ideally with a salute, or a hand on heart," Trump wrote on Twitter.

The statement was a response to quarterback Drew Brees, who apologised this week for equating the kneeling protest with disrespecting the American flag.

On Thursday, several players, including reigning Super Bowl MVP Patrick Mahomes of the Kansas City Chiefs, appeared in a video on social media calling for the league to "admit wrong in silencing" players and to support protests.

"How many times do we need to ask you to listen to your players?" Chiefs player Tyrann Mathieu said in the video.