"The policy adopted today was approved in concert with the NFL's ongoing commitment to local communities and our country — one that is extraordinary in its scope, resources, and alignment with our players," Goodell said in a statement. "We are dedicated to continuing our collaboration with players to advance the goals of justice and fairness in all corners of our society."
Goodell said that when the new season kicks off in the fall, all players and NFL team personnel "shall stand and show respect for the flag and the anthem."
He said players who choose not to stand for the national anthem under the new policy, which was panned by the players union, will be allowed to remain in the locker room until the performance of the "Star-Spangled Banner" is complete.
Goodell said "it was unfortunate" that on-field protests by players taking a knee during the national anthem "created a false perception among many that thousands of NFL players were unpatriotic. This is not and was never the case."
He said the new policy was "reaffirmed" by all 32 teams of the National Football League.
The previous policy required players to be on the field for the anthem but said only that they "should" stand.
Teams will be subjected to fines if a player or team personnel defies the new policy. Teams are also being given the option of imposing fines on any team personnel, including players, for the infraction.
However, Christopher Johnson, chairman of the New York Jets, said he will not stop his players from continuing to take a knee on the field during the national anthem.
"I do not like imposing any club-specific rules," Johnson said in an interview with Newsday of Long Island. “If somebody [on the Jets] takes a knee, that fine will be borne by the organization, by me, not the players. I never want to put restrictions on the speech of our players. Do I prefer that they stand? Of course. But I understand if they felt the need to protest."
Johnson is the brother of Jets owner Woody Johnson, who is also Trump's ambassador to the United Kingdom.
Christopher Johnson said the players have the right to protest "big complicated issues" the nation is struggling with.
"I don't want to come down on them like a ton of bricks, and I won't," Johnson said. "There will be no club fines or suspensions or any sort of repercussions. If the team gets fined, that’s just something I'll have to bear."
Goodell praised players for causing "awareness and action around issues that must be addressed," but said there are alternative avenues to do so off the field.
"The platform that we have created together is certainly unique in professional sports and quite likely in American business," Goodell said. "We are honored to work with our players to drive progress."
But the NFL Players Association said league officials did not consult with the union in the development of the new policy.
"NFL players have shown their patriotism through their social activism, their community service, in support of our military and law enforcement and yes, through their protests to raise awareness about the issues they care about," the NFLPA said in a statement.
"The vote by NFL club CEOs today contradicts the statements made to our player leadership by Commissioner Roger Goodell and the Chairman of the NFL's Management Council John Mara about the principles, values and patriotism of our League," the statement reads. "Our union will review the new 'policy' and challenge any aspect of it that is inconsistent with the collective bargaining agreement."