He said: “It’s obviously disappointing, but we have to keep our spirits high in the camp and we have to take positivity into the next game, which is obviously an important game for the country.
“Sometimes it’s difficult to keep the positivity and spirits up, especially after a defeat, but we were playing against a good team.
“So it’s definitely a good test for us, but we have to look forward to the next game.”
He added: “I wouldn’t say (the defeat to Belgium is a) reality check.
“!We know it’s early on in the process of what we’re trying to do, but this was just a chance to try and prove it.
“It was difficult, but we have an opportunity now to improve in the days of training before the next game.”
Alexander-Arnold said: “Very disappointing. We came into the game wanting to win it, obviously we never won it, but we are still in the round of 16 and something to look forward to.
“They controlled a lot of possession. We had our chances and never took them.
“Equally they had one big chance and they took it. It was a good goal at the end of the day.
“We can only regret the chances we didn’t take. But we are in the round of 16, out the group stages, which was the first objective for the team.”
On the challenge of Colombia, the Liverpool player said: “There are no easy games ahead of us.
“It will be very tough. If you look back to the last World Cup they did unbelievably well.
“They have shown in this World Cup that they can bounce back from a defeat and win games. It is not going to be easy at all.”