Gareth Southgate says England are determined "more than ever" to take a knee during the forthcoming European Championship.
Some fans booed when players made the anti-racism stance before Wednesday's warm-up match against Austria at the Riverside Stadium.
Three Lions boss Southgate said at a press conference ahead of Sunday's game against Romania at the same venue: "The first thing is we are collectively really disappointed it (the booing) happened.
"Some people decide to boo – I think those people should put themselves in the shoes of those young players and how that must feel, and if that was their children, how would they feel about their kids being in that sort of situation.
"The most important thing for our players is to know that we are totally united on it, we're totally committed to supporting each other, supporting the team.
"We feel more than ever determined to take the knee through this tournament. We accept there might be an adverse reaction and we're just going to ignore that and move forward.
"I think the players are sick of talking about the consequences of should they, shouldn't they. They've had enough really. As far as I'm concerned they are not going to take more questions on this through the tournament. If it happens, it happens. They're very clear. Their voices have been heard loud and clear.
"They are making their stand but they want to talk about the football and want the focus to be on the football."
Southgate was joined at the press conference by midfielder Kalvin Phillips, who said he had felt "confused and disappointed" by the booing, adding: "I think I was just happy that the boos got cancelled out by the fans cheering in the end, but I don't think it's a great situation, especially for us players.
"All we can do is just focus on the game and speak about it afterwards. And I think the team spoke about it together and we came up with the conclusion that, regardless of what goes on around, we're still going to participate in the kneeling and I think that's a great idea."
Southgate also spoke about the disappointment after Trent Alexander-Arnold was ruled out of the Euros on Thursday by a thigh injury suffered in the 1-0 win against Austria.
Southgate said: "You know how rare these opportunities are and even though he's a young player who is going to have those opportunities again, I firmly believe that that's a really difficult moment, for him especially. It's a big disappointment for us of course as well, but you can't help but first and foremost feel for Trent in this situation.
"The one thing I was pleased about, in that immediately after the game I didn't like the look of the injury, at least it sounds as though he should be fine for pre-season and next season.
"But that is a very small positive in the situation he is in. He was very upset, bitterly disappointed, and in those moments everybody is thinking about him."
When asked for his thoughts in terms of replacing the Liverpool full-back in his squad, Southgate stressed a decision would be made after Sunday's match and the importance of getting "the positional balance right for the whole squad".
Southgate was also asked if there was a danger Harry Maguire, who is recovering from an ankle injury, would not be able to play any part in the Euros, and he said: "With any injury, it's impossible to predict 100 per cent.
"Our medical team are pleased with his progress, and particularly over the last couple of days.
"We've picked a squad on the basis that if we didn't have him we've got the players to come in. And if he's able to be fit and available then that's a bonus for us."
Regarding Jordan Henderson, who is set on Sunday to make his first appearance since undergoing groin surgery in February, Southgate said: "The last two, three days training have been a lot more positive for him. He's been visibly happier within himself I think and that's a positive sign."